olymmath

GAIC Math 2024

GAIC Math (MathOdyssey) 2024.

Other problems

Problem 1

Let S={1,2,⋯2024}S=\left\{ 1,2,\cdots 2024 \right\}, if the set of any nn pairwise prime numbers in SS has at least one prime number, the minimum value of nn is \underline{\hspace{2cm}}.

Problem 2

Let Al=(4l+1)(4l+2)⋯(4(55+1)l)A_l = (4l+1)(4l+2) \cdots \left(4(5^5+1)l\right). Given a positive integer ll such that 525l∣Al5^{25l} \mid A_l and 525l+1∤Al5^{25l+1} \nmid A_l, the minimum value of ll satisfying these conditions is \underline{\hspace{2cm}}.

Problem 3

Sasha collects coins and stickers, with fewer coins than stickers, but at least 1 coin. Sasha chooses a positive number t>1t > 1 (not necessarily an integer). If he increases the number of coins by a factor of tt, then he will have a total of 100 items in his collection. If he increases the number of stickers by a factor of tt, then he will have a total of 101 items in his collection. If Sasha originally had more than 50 stickers, then he originally had \underline{\hspace{2cm}} stickers.

Problem 4

Let nn be a positive integer. An integer kk is called a "fan" of nn if and only if 0⩽k⩽n−10 \leqslant k \leqslant n-1 and there exist integers xx, yy, z∈Zz \in \mathbf{Z} such that x2+y2+z2≡0(modn)x^2+y^2+z^2 \equiv 0 (\mathrm{mod} n) and xyz≡k(modn)xyz \equiv k (\mathrm{mod} n). Let f(n)f(n) denote the number of fans of nn. Then f(2020) = \underline{\hspace{2cm}}.

Problem 5

Four positive integers satisfy a3=b2a^3=b^2, c5=d4c^5=d^4, and c−a=77c-a=77. Then, d−b=d-b= \underline{\hspace{2cm}}.

Problem 6

The smallest nn such that both 3n+13n+1 and 5n+15n+1 are perfect squares is \underline{\hspace{2cm}}.

Problem 7

Find the largest positive integer nn such that the product of the numbers n,n+1,n+2,⋯ ,n+100n, n+1, n+2,\cdots, n+100 is divisible by the square of one of these numbers.

Problem 8

Given a positive integer xx with mm digits in its decimal representation, and let x3x^3 have nn digits. Which of the following options cannot be the value of m+nm + n?

\begin{align*} \text{A)}\ & 2022 & \text{B)}\ & 2023\ \text{C)}\ & 2024 & \text{D)}\ & 2025\ \end{align*}

Problem 9

Positive integers aa, bb, and cc satisfy a>b>c>1a > b > c > 1, and also satisfy abc∣(ab−1)(bc−1)(ca−1)abc \mid (ab - 1)(bc - 1)(ca - 1). There are \underline{\hspace{2cm}} possible sets of (a,b,c)(a, b, c).

Problem 10

There are \underline{\hspace{2cm}} sets of positive integers a≤b≤ca \leq b \leq c such that ab−cab - c, bc−abc - a, and ca−bca - b are all powers of 2.

Problem 11

Define the function f(x)=[x[x]]f(x) =[x[x]], where [x][x] represents the largest integer not exceeding xx. For example, [−2.5]=−3[-2.5] = -3.For a positive integer nn, let ana_n be the number of elements in the range set of f(x)f(x) when x∈[0,n)x \in [0,n). Then the minimum value of an+90n\frac{a_n + 90}{n} is \underline{\hspace{2cm}}.

Problem 12

If a positive integer's sum of all its positive divisors is twice the number itself, then it is called a perfect number. If a positive integer nn satisfies both n−1n-1 and n(n+1)2\frac{n(n+1)}{2} being perfect numbers, then n=n= \underline{\hspace{2cm}}.

Problem 13

Try to find all prime numbers with the shape pp+1p^p+1(pp is a natural number) that have no more than 19 digits and what the sum of these prime numbers is.

Problem 14

For any positive integer q0q_0, consider a sequence q1,q2,⋯ ,qnq_1,q_2,\cdots,q_n defined by qi=(qi−1−1)3+3(i=1,2,⋯ ,n)q_i=\left(q_{i-1}-1\right)^3+3\left(i=1,2,\cdots,n\right). If every qi(i=1,2,⋯ ,n)q_i\left(i=1,2,\cdots,n\right) is a power of prime, then the maximum possible value of nn is \underline{\hspace{2cm}}.

Problem 15

The first digit before the decimal point in the decimal representation of (2+5)2000(\sqrt{2} + \sqrt{5})^{2000} is \underline{\hspace{2cm}} and after the decimal point is \underline{\hspace{2cm}}.

Problem 16

NN is a 5-digit number composed of 5 different non-zero digits, and NN is equal to the sum of all three digits formed by 3 different digits in these 5 digits, then the sum of all such 5-digit NN is \underline{\hspace{2cm}}.

Problem 17

If the last three digits of a positive integer nn cubed are 888, then the minimum value of nn is \underline{\hspace{2cm}}.

Problem 18

aa, bb are both two-digit positive integers, 100a+b100a+b and 201a+b201a+b are both four-digit perfect squares, then a+b=a+b= \underline{\hspace{2cm}}.

Problem 19

For a positive integer nn, which can be uniquely expressed as the sum of the squares of 5 or fewer positive integers (where two expressions with different summation orders are considered the same, such as 32+423^2+4^2 and 42+324^2+3^2 are considered the same expression of 25), then the sum of all the nn that satisfy the conditions is \underline{\hspace{2cm}}.

Problem 20

Given that the product of the digits of a natural number xx is equal to 44x−8686844x-86868, and the sum of its digits is a perfect cube. Then the sum of all such natural numbers xx is \underline{\hspace{2cm}}.

Problem 21

Given aa is a prime number and bb is a positive integer such that 9(2a+b)2=509(4a+511b)9(2a+b)^2=509(4a+511b), we need to find the values of aa and bb.

Problem 22

Let φ(n)\varphi(n) denote the number of natural numbers coprime to and less than nn. Then, when φ(pq)=3p+q\varphi(pq)=3p+q, what is the sum of pp and qq?

Problem 23

Consider the sequence {Sn}\{S_n\} constructed as follows: S1={1,1}S_1=\{1,1\}, S2={1,2,1}S_2=\{1,2,1\}, S3={1,3,2,3,1}S_3=\{1,3,2,3,1\}, and in general, if Sk={a1,a2,⋯ ,an}S_k=\{a_1,a_2,\cdots,a_n\}, then Sk+1={a1,a1+a2,a2,a2+a3,⋯ ,an−1+an,an}S_{k+1}=\{a_1,a_1+a_2,a_2,a_2+a_3,\cdots,a_{n-1}+a_n,a_n\}. What is the number of terms equal to 19881988 in S1988S_{1988}?

Problem 24

For a natural number nn, let S(n)S(n) denote the sum of its digits. For example, S(611)=6+1+1=8S(611)=6+1+1=8. Let aa, bb, and cc be three-digit numbers such that a+b+c=2005a+b+c=2005, and let MM be the maximum value of S(a)+S(b)+S(c)S(a)+S(b)+S(c). How many sets (a,b,c)(a,b,c) satisfy S(a)+S(b)+S(c)=MS(a)+S(b)+S(c)=M?

Problem 25

For a natural number nn, let K(n,0)=∅K(n,0)=\varnothing. For any non-negative integers mm and nn, define K(n,m+1)K(n,m+1) as the set of elements kk such that 1≤k≤n1\leq k\leq n and K(k,m)∩K(n−k,m)=∅K(k,m)\cap K(n-k,m)=\varnothing, then the set K(2004,2004)K(2004,2004) contains \underline{\hspace{2cm}} elements.

Problem 26

Let T={0,1,2,3,4,5,6}T=\{0,1,2,3,4,5,6\} and M={a17+a272+a373+a474∣ai∈T,i=1,2,3,4}M=\left\{\left.\frac{a_1}{7}+\frac{a_2}{7^2}+\frac{a_3}{7^3}+\frac{a_4}{7^4}\right|a_i\in T,i=1,2,3,4\right\}. If the elements of MM are arranged in descending order, then the 2005th number is \underline{\hspace{2cm}}. \begin{align*} \text{A)}\ & \frac{5}{7}+\frac{5}{7^2}+\frac{6}{7^3}+\frac{3}{7^4}& \text{B)}\ & \frac{5}{7}+\frac{5}{7^2}+\frac{6}{7^3}+\frac{2}{7^4}\ \text{C)}\ & \frac{1}{7}+\frac{1}{7^2}+\frac{0}{7^3}+\frac{4}{7^4}& \text{D)}\ & \frac{1}{7}+\frac{1}{7^2}+\frac{0}{7^3}+\frac{3}{7^4} \ \end{align*}

Problem 27

Mutually prime positive integers pn,qnp_n, q_n satisfy Pnqn=1+12+13+⋯+1n\frac{P_n}{q_n}=1+\frac12+\frac13+\cdots+\frac1n. The sum of all positive integers nn such that 3∣pn3|p_n is \underline{\hspace{2cm}}.

Problem 28

Given xx and yy are prime numbers. The sum of the values of yy in the solutions of the indeterminate equation x2−y2=xy2−19x^2-y^2=xy^2-19 is \underline{\hspace{2cm}}.

Problem 29

The number of non-zero integer pairs (a,b)(a,b) for which (a3+b)(a+b3)=(a+b)4\left(a^3+b\right)\left(a+b^3\right)=(a+b)^4 holds is \underline{\hspace{2cm}}.

Problem 30

If the sum of the digits of a natural number α\alpha equals 7, then aa is called an "auspicious number". Arrange all "auspicious numbers" in ascending order a1,a2,a3,⋯a_1,a_2,a_3,\cdots, if an=2005a_n=2005, then a5na_{5n}=\underline{\hspace{2cm}}.

Problem 31

The number of integers nn in the interval 1≤n≤1061\leq n\leq10^6 such that the equation n=xyn=x^y has non-negative integer solutions x,yx,y, and x≠nx\neq n is \underline{\hspace{2cm}}.

Problem 32

Let pp be a real number. If all three roots of the cubic equation 5x3−5(p+1)x2+(71p−1)x+1=66p5x^3 - 5(p+1)x^2 + (71p - 1)x + 1 = 66p are natural numbers, then the sum of all possible values of pp is \underline{\hspace{2cm}}.

Problem 33

The number of triples of positive integers (a,b,c)(a, b, c) satisfying a2+b2+c2=2005a^2 + b^2 + c^2 = 2005 and a≤b≤ca \leq b \leq c is \underline{\hspace{2cm}}.

Problem 34

The maximum positive integer kk that satisfies 1991k∣199019911992+1992199119901991^k \mid 1990^{19911992} + 1992^{19911990} is \underline{\hspace{2cm}}.

Problem 35

Let aa and bb be positive integers such that 79∣(a+77b)79 \mid (a + 77b) and 77∣(a+79b)77 \mid (a + 79b). Then the smallest possible value of the sum a+ba + b is \underline{\hspace{2cm}}.

Problem 36

Let ai,bi (i=1,2,…,n)a_i, b_i \ (i=1,2,\ldots,n) be rational numbers such that for any real number xx, we have x2+x+4=∑i=1n(aix+bi)2x^2 + x + 4 = \sum_{i=1}^{n} (a_{i}x + b_{i})^{2}. Then the minimum possible value of nn is \underline{\hspace{2cm}}.

Problem 37

Let α\alpha and β\beta be the two roots of the equation x2−x−1=0x^2 - x - 1 = 0. Define αn=αn−βnα−β\alpha_n = \frac{\alpha^n - \beta^n}{\alpha - \beta} for n=1,2,…n = 1, 2, \ldots. For some positive integers aa and bb, with a<ba < b, if for any positive integer nn, bb divides an−2nana_n - 2na^n, then the sum of all such positive integers bb is \underline{\hspace{2cm}}.

Problem 38

Let nn be a natural number greater than 33 such that 1+Cn1+Cn2+Cn31+C_n^1+C_n^2+C_n^3 divides 220002^{2000}. Then, the sum of all such nn satisfying this condition is \underline{\hspace{2cm}}.

Problem 39

In the decimal representation, the product of the digits of kk equals 258k−211\frac{25}{8}k-211. Then the sum of all positive integers kk satisfying this condition is \underline{\hspace{2cm}}.

Problem 40

Let nn be an integer, and let p(n)p(n) denote the product of its digits (in decimal representation). Then the sum of all nn such that 10 p(n)=n2+4n−200510\:p(n)=n^{2}+4n-2005 is \underline{\hspace{2cm}}.

Problem 41

There are some positive integers with more than two digits, such that each pair of adjacent digits forms a perfect square. Then the sum of all positive integers satisfying the above conditions is \underline{\hspace{2cm}}.

Problem 42

Let α\alpha be an integer, and ∣α∣≤2005|\alpha|\leq2005. The number of values of α\alpha that make the system of equations {x2=y+α,y2=x+α\begin{cases}x^{2}=y+\alpha,\\y^{2}=x+\alpha\end{cases} have integer solutions is \underline{\hspace{2cm}}.

Problem 43

Divide the set S={1,2,⋯ ,2006}S=\{1,2,\cdots,2006\} into two disjoint subsets AA and BB such that:

(1) B∈AB \in A;

(2) If a∈Aa\in A and b∈Bb\in B with a+b∈Sa+b\in S, then a+b∈Ba+b\in B;

(3) If a∈Aa\in A, b∈Bb\in B, and ab∈Sa b\in S, then ab∈Aa b\in A.

The number of elements in set AA is \underline{\hspace{2cm}}.

Problem 44

Let SS be a finite set of integers. Suppose that for any two distinct elements p,q∈Sp, q \in S, there exist three elements aa, bb, c∈Sc \in S (not necessarily distinct, and a≠0a \neq 0) such that the polynomial F(x)=αx2+bx+cF(x) = \alpha x^2 + bx + c satisfies F(p)=F(q)=0F(p) = F(q) = 0. The maximum number of elements in SS is \underline{\hspace{2cm}}

Problem 45

A natural number whose last four digits are 2022 and is divisible by 2003 has a minimum value of _____.

Problem 46

The number of positive integer solution in (x2+2)(y2+3)(z2+4)=60xyz\left(x^{2}+2\right)\left(y^{2}+3\right)\left(z^{2}+4\right)=60 x y z is _____.

Problem 47

The number of integers satisfying the condition that x2+5n+1x^2+5n+1 is a perfect square is known to be _____.

Problem 48

If p, q, r are prime numbers such that p+q+r=1000p+q+r=1000, then the remainder when p2q2r2p^{2} q^{2} r^{2} is divided by 48 is _____.

Problem 49

Given x,y,zx, y, z are integers, and 10x3+20y3+2006xyz=2007z310x^{3}+20y^{3}+2006 xyz=2007z^{3}, then the maximum of x+y+zx+y+z is _____.

Problem 50

For a positive integer nn, if the first two digits of 5n5^{n} and 2n2^{n} are the same, denoted as aa and bb respectively, then the value of the two-digit number ab‾\overline{ab} is _____.

Problem 51

The remainder when 2020×2019×⋯×197744!\frac{2020 \times 2019 \times \cdots \times 1977}{44!} is divided by 2021 is _____.

Problem 52

Given the sequence {an}:a1=1,an+1=3an+13−an\{a_n\}: a_1=1, a_{n+1}=\frac{\sqrt{3}a_n+1}{\sqrt{3}-a_n}, then ∑n=12022an=_____\sum\limits_{n=1}^{2022}a_n=\_\_\_\_\_.

Problem 53

Given 2bx2+ax+1−b≥02bx^2 + ax + 1 - b \geq 0 holds for x∈[−1,1]x \in [-1, 1], find the maximum value of a+ba + b.

Problem 54

Given x,y∈[0,+∞)x,y \in [0,+\infty), and satisfying x3+y3+6xy=8x^3+y^3+6xy=8. Then the minimum value of 2x2+y2=_____2x^2+y^2=\_\_\_\_\_.

Problem 55

Given f(x)f(x) and g(x)g(x) are two quadratic functions with the coefficient of the quadratic term being 1 for both. If g(6)=35,f(−1)g(−1)=f(1)g(1)=2120g(6)=35,\frac{f(-1)}{g(-1)}=\frac{f(1)}{g(1)}=\frac{21}{20}, then f(6)=_____f(6)=\_\_\_\_\_.

Problem 56

Given (n+1)a+1−na+1<na(a+1)<nan+1−(n−1)a+1(−1<a<0)1◯(n + 1)^{a+1} - n^{a+1} < n a^(a + 1) < n a^{n+1} - (n - 1)^{a+1} (-1 < a < 0) \textcircled{1}. Letx=∑k=41061k3x=\sum\limits_{k=4}^{106}\frac{1}{\sqrt[3]{k}}, then the integer part of x is _____.

Problem 57

Let a1=π6,an∈(0,π2)a_1=\frac{\pi}{6}, a_n \in (0,\frac{\pi}{2}), and tan⁡an+1⋅cos⁡an=1(n≥1)\tan a_{n+1}\cdot \cos a_n=1 (n\geq 1). If ∏k=1msin⁡ak=1100\prod\limits_{k=1}^m \sin a_k=\frac{1}{100}, then m=m= _____.

Problem 58

Let y=f(x)y=f(x) be a strictly monotonically increasing function, and let its inverse function be y=g(x)y=g(x). Let x1,x2x_1, x_2 be the solutions to the equations f(x)+x=2f(x)+x=2 and g(x)+x=2g(x)+x=2 respectively. Then x1+x2=_____x_1+x_2=\_\_\_\_\_.

Problem 59

Let x0>0,x0≠3,Q(x0,0),P(0,4)x_0>0, x_0 \neq \sqrt{3}, Q(x_0,0), P(0,4), and the line PQ intersects the hyperbola x2−y23=1x^2-\frac{y^2}{3}=1 at points A and B. If PQ→=tQA→=(2−t)QB→\overrightarrow{PQ}=t\overrightarrow{QA}=(2-t)\overrightarrow{QB}, then x0=_____x_0=\_\_\_\_\_.

Problem 60

Assuming sequence Fn{F_n} satisfying: F1=F2=1,Fn+1=Fn+Fn−1(n≥2)F_1=F_2=1, F_{n+1}=F_n+F_{n-1} (n\geq 2). Then the number of sets of positive integers (x,y)(x,y) that satisfy 5Fx−3Fy=15F_x-3F_y=1 is

Problem 61

For some positive integers nn, there exists a positive integer k≥2k\geq 2 such that for positive integers x1,x2,...,xkx_1,x_2,...,x_k satisfying the given condition, ∑i=1k−1xixi+1=n\sum\limits_{i=1}^{k-1}x_ix_{i+1}=n, ∑i=1kxi=2019\sum\limits_{i=1}^{k}x_i=2019 the number of such positive integers is _____.

Problem 62

Considering all non-increasing functions f:{1,2,⋯ ,10}→{1,2,⋯ ,10}f:\{1,2,\cdots,10\} \rightarrow \{1,2,\cdots,10\}, some of these functions have fixed points, while others do not. The difference in the number of these two types of functions is _____.

Problem 63

Given an integer coefficient polynomial P(x)P(x) satisfying: P(−1)=−4,P(−3)=−40,P(−5)=−156P(-1)=-4, P(-3)=-40, P(-5)=-156. The maximum number of solutions x for P(P(x))=x2P(P(x))=x^2 is _____.

Problem 64

Given hyperbola Γ:x2a2−y2b2=1\Gamma: \frac{x^2}{a^2}-\frac{y^2}{b^2}=1 passes the point M(3,2)M(3,\sqrt{2}), line ll passes its right focus F(2,0)F(2,0) and cross the right branch of Γ\Gamma at points AA and BB, and cross the y-axis at point P. If PA→=mAF→,PB→=nBF→\overrightarrow{PA}=m\overrightarrow{AF}, \overrightarrow{PB}=n\overrightarrow{BF}, then m+n=m+n= _____.

Problem 65

Let positive real numbers x1,x2,x3,x4x_1, x_2, x_3, x_4 satisfying x1x2+x2x3+x3x4+x4x1=x1x3+x2x4x_1x_2+x_2x_3+x_3x_4+x_4x_1=x_1x_3+x_2x_4. Then the minimum of f=x1x2+x2x3+x3x4+x4x1f=\frac{x_1}{x_2}+\frac{x_2}{x_3}+\frac{x_3}{x_4}+\frac{x_4}{x_1} is _____.

Problem 66

Given sequence {an}\{a_n\} satisfying a1=a,an+1=2(an+1an)−3a_1=a, a_{n+1}=2(a_n+\frac{1}{a_n})-3. If an+1>an(n∈Z+)a_{n+1} > a_n (n \in Z_{+}). The range of real number aa is _____.

Problem 67

Given positive number α,β,γ,δ\alpha, \beta, \gamma, \delta satisfying α+β+γ+δ=2π\alpha+\beta+\gamma+\delta=2\pi, and k=3tan⁡α1+sec⁡α=4tan⁡β1+sec⁡β=5tan⁡γ1+sec⁡γ=6tan⁡δ1+sec⁡δk=\frac{3\tan\alpha}{1+\sec \alpha}=\frac{4\tan \beta}{1+\sec \beta}=\frac{5\tan \gamma}{1+\sec \gamma}=\frac{6\tan\delta}{1+\sec\delta}, then kk= _____.

Problem 68

Let A={1,2,⋯ ,6}A=\{1,2,\cdots,6\}, function f:A→Af:A \rightarrow A. Mark p(f)=f(1)⋯f(6)p(f)=f(1)\cdots f(6). Then the number of functions that make p(f)∣36p(f)|36 is _____.

Problem 69

If unit complex number a,ba, b satisfy abˉ+aˉb=3a\bar{b}+\bar{a}b = \sqrt{3}, then ∣a−b∣=|a-b|= _____.

Problem 70

The right focus F1F_1 of the ellipse Γ1:x224+y2b2=1(0<b<26)\Gamma_1: \frac{x^2}{24}+\frac{y^2}{b^2}=1 (0<b<2\sqrt{6}) coincides with the focus of the parabola Γ2:y2=4px(p∈Z+)\Gamma_2: y^2=4px(p \in Z_{+}). The line ll passing through the point F1F_1 with a positive integer slope intersects the ellipse Γ1\Gamma_1 at points A and B, and intersects the parabola Γ2\Gamma_2 at points C and D. If 13∣AB∣=6∣CD∣13|AB|=\sqrt{6}|CD|, then b2+p=b^2+p= _____.

Problem 71

Given that p(x)p(x) is a quintic polynomial. If x=0x=0 is a triple root of p(x)+1=0p(x)+1=0 and x=1x=1 is a triple root of p(x)−1=0p(x)-1=0, then the coefficient of the x3x^3 term in the expression of p(x)p(x) is _____.

Problem 72

Set X={1,2,⋯ ,10}X=\{1,2,\cdots,10\}, mapping f:X→Xf:X\rightarrow X satisfy:\ (1) f∘f=Ixf\circ f = I_x, where, f∘ff\circ f is a composite mapping, IxI_x is an identity mapping on X.\ (2) ∣f(i)−i∣=2|f(i)-i|=2, for any i∈Xi\in X.\ Then the number of mapping ff is _____.

Problem 73

Given a integer coefficient polynomial of degree 2022 with leading coefficient is 1, how many roots can it possibly have in the interval (0,1) as maximum?

Problem 74

The system of equations {x2y+y2z+z2=0,z3+z2y+zy3+x2y=14(x4+y4)\left\{\begin{array}{l}x^{2} y+y^{2} z+z^{2}=0, \\ z^{3}+z^{2} y+z y^{3}+x^{2} y=\frac{1}{4}\left(x^{4}+y^{4}\right)\end{array}\right. has how many sets of real solution (x,y,z)(x,y,z) ?.

Problem 75

Set x,y,zx, y, z are real numbers, satisfying x2+y2+z2=1x^{2}+y^{2}+z^{2}=1. Then the maximum and minimum of (x−y)(y−z)(x−z)(x-y)(y-z)(x-z) are

Problem 76

If there are a total of 95 numbers, each of which can take any value in +1 or -1, and it is known that the sum of the pairwise products of these 95 numbers is positive, then what is the minimum possible value of this positive sum?

Problem 77

A monotonically increasing sequence of positive integers, starting from the third term, with each subsequent term being the sum of the preceding two terms. If its seventh term is 120, then its eighth term is _____.

Problem 78

Sequence {an}\left\{a_{n}\right\} satisfy a0=0,a1=1a_{0}=0, a_{1}=1, and for any positive integer n\mathrm{n}, we have a2n=an′a2n+1=an+1a_{2 n}=a_{n^{\prime}} a_{2 n+1}=a_{n}+1, then a2024=a_{2024}=_____.

Problem 79

Non-negative real numbers x,y,z\mathrm{x}, \mathrm{y}, \mathrm{z} satisfy 4x2+4y2+z2+2z=34 x^{2}+4 y^{2}+z^{2}+2 z=3, then the minimum of 5x+4y+3z5 \mathrm{x}+4 \mathrm{y}+3 \mathrm{z} is _____.

Problem 80

Real numbers x,yx, y satisfy 2x−5y≤−62 x-5 y \leq-6 and 3x+6y≤253 x+6 y \leq 25, then the maximum value of 9x+y9 x+y is _____.

Problem 81

The sum of the maximum element and minimum element in set {3a+b∣1≤a≤b≤2}\left\{\left.\frac{3}{a}+b \right\rvert 1 \leq a \leq b \leq 2\right\} is _____.

Problem 82

A monotonically increasing function f(x)\mathrm{f}(\mathrm{x}) defined on R+R^{+} satisfies f(f(x)+2x)=−1\mathrm{f}\left(\mathrm{f}(\mathrm{x})+\frac{2}{\mathrm{x}}\right)=-1 consistently holds within its domain, then f(1)=\mathrm{f}(1)=_____.

Problem 83

Given set: A={x+y∣x29+y2=1,x+y∈Z+},B={2x+y∣x,y∈A,x<y}A=\left\{x+y \left\lvert \frac{x^{2}}{9}+y^{2}=1\right., x+y \in \mathbf{Z}_{+}\right\}, B=\{2 x+y \mid x, y \in A, x<y\}, C={2x+y∣x,y∈A,x>y}C=\{2 x+y \mid x, y \in A, x>y\}. Then the sum of all elements in B∩CB \cap C is

Problem 84

Given a hyperbola Γ:x27−y25=1\Gamma: \frac{x^{2}}{7}-\frac{y^{2}}{5}=1, a line l:ax+by+1=0l: a x+b y+1=0 intersects Γ\Gamma at point AA. A tangent to Γ\Gamma drawn through point AA is perpendicular to the line ll. Then 7a2−5b2=\frac{7}{a^{2}}-\frac{5}{b^{2}}=_____.

Problem 85

In the Cartesian coordinate plane xOyx O y, point A(a,0),B(0,b),C(0,4)A(a, 0), B(0, b), C(0,4), moving point DD satisfies ∣CD∣=1|C D|=1. If the maximum value of ∣OA→+OB→+OD→∣|\overrightarrow{O A}+\overrightarrow{O B}+\overrightarrow{O D}| is 6, then the minimum value of a2+b2a^{2}+b^{2} is _____.

Problem 86

Given nn is positive integer, for i=1,2,⋯ ,ni=1,2, \cdots, n, positive integer aia_{i} and positive even number bib_{i} satisfy 0<aibi<10<\frac{a_{i}}{b_{i}}<1, and for any positive integers i1,i2(1≤i1<i2≤n),ai1≠ai2i_{1}, i_{2}\left(1 \leq i_{1}<i_{2} \leq n\right), a_{i_{1}} \neq a_{i_{2}} and bi1≠bi2b_{i_{1}} \neq b_{i_{2}} at least one holds true. If for any positive integer nn and all positive integers aia_{i} and positive even numbers bib_{i} satisfy the above conditions, we all have ∑i=1nbin32≥c\frac{\sum_{i=1}^{n} b_{i}}{n^{\frac{3}{2}}} \geq c, then the maximum value of real number cc is _____.

Problem 87

In a cube ABCD−A1B1C1D1ABCD-A_1B_1C_1D_1, AA1=1AA_1=1, E, F are the midpoints of edges CC1,DD1CC_1, DD_1, then the area of the cross-section obtained by the plane AEF intersecting the circumscribed sphere of the cube is _____.

Problem 88

In tetrahedron ABCDABCD, triangle ABCABC is an equilateral triangle, ∠BCD=90∘\angle BCD=90^{\circ}, BC=CD=1BC=CD=1,AC=3AC=\sqrt{3},EE and FF are the midpoints of edges BDBD and ACAC respectively. Then the cosine of the angle formed by lines AEAE and BFBF is _____.

Problem 89

Let P be a point inside triangle ABC, and 2PA→=PB→+PC→=0\overrightarrow{PA} = \overrightarrow{PB} + \overrightarrow{PC}=0. If ∠BAC=π3,BC=2\angle BAC = \frac{\pi}{3}, BC=2, then the maximum value of PB→⋅PC→\overrightarrow{PB}\cdot\overrightarrow{PC} is _____.

Problem 90

A rectangular solid whose length, width, and height are all natural numbers, and the sum of all its edge lengths equals its volume, is called a "perfect rectangular solid. The maximum value of the volume of a perfect rectangular solid is _____.

Problem 91

In the convex quadrilateral ABCDA B C D inscribed in a circle, if AB→+3BC→+2CD→+4DA→=0\overrightarrow{A B}+3 \overrightarrow{B C}+2 \overrightarrow{C D}+4 \overrightarrow{D A}=0, and ∣AC→∣=4|\overrightarrow{A C}|=4, then the maximum of ∣AB→∣+∣BC→∣|\overrightarrow{A B}|+|\overrightarrow{B C}| is _____.

Problem 92

Given that the edge length of the cube ABCD−A1B1C1D1A B C D-A_{1} B_{1} C_{1} D_{1} is 11, where, EE is the middle point of ABA B, FF is the middle point of CC1C C_{1}. Then the distance from point DD to the plane passing through the three points D1,E,FD_{1}, E, F is _____.

Problem 93

Given that the vertices of triangle △OAB\triangle OAB are O(0,0)O(0,0), A(4,43)A(4,4\sqrt{3}), and B(8,0)B(8,0), with the incenter denoted as II, let Γ\Gamma be a circle passing through points AA and BB, intersecting circle ⊙I\odot I at points PP and QQ. If the tangents drawn through points PP and QQ are perpendicular, then the radius of circle Γ\Gamma is _____.

Problem 94

A person has some 2×5×82 \times 5 \times 8 bricks and some 2×3×72 \times 3 \times 7 bricks, as well as a 10×11×1410 \times 11 \times 14 box. All bricks and the box are rectangular prisms. He wants to pack all the bricks into the box so that the bricks can fill the entire box. The number of bricks he can fit into the box is _____ pieces.

Problem 95

Let aa be an acute angle not exceeding 45∘45^\circ. If cot⁡2a−3=sec⁡a\cot 2a - \sqrt{3} = \sec a, then a=a = _____ degrees.

Problem 96

Known that there is a regular 200-gon A1A2…A200A_{1}A_{2} \ldots A_{200}, connecting the diagonals AiAi+9(i=1,2,…,200)A_{i}A_{i+9}(\mathrm{i}=1,2, \ldots, 200), where Ai+200=Ai(i=1,2,…,9)A_{i+200}=A_{i}(i=1,2, \ldots, 9). Then there are a total of _____ distinct intersection points inside the regular 200-gon.

Problem 97

The distance between the highest point of the ellipse obtained by counterclockwise rotating the ellipse x22+y2=1\frac{x^{2}}{2}+y^{2}=1 about the origin by 45 degrees and the origin is:_____.

Problem 98

A convex n\mathrm{n}-gon with interior angles of n\mathrm{n} degrees each, all integers, and all different. The degree measure of the largest interior angle is three times the degree measure of the smallest interior angle. The maximum value that nn can take is _____.

Problem 99

In triangle ABC\mathrm{ABC} with its incenter I\mathrm{I}, if 3IA→+4IB→+5IC→=0→3\overrightarrow{IA} + 4\overrightarrow{IB} + 5\overrightarrow{IC} = \overrightarrow{0}, then the measure of angle C\mathrm{C} is _____.

Problem 100

Given the circle x2+y2=4x^2 + y^2 = 4 and the point P(2,1)\mathrm{P}(2,1), two mutually perpendicular lines are drawn through point P\mathrm{P}, intersecting the circle at points A,B\mathrm{A}, \mathrm{B} and C,D\mathrm{C}, \mathrm{D} respectively. Point A\mathrm{A} lies inside the line segment PBPB, and point D\mathrm{D} lies inside the line segment PCPC. The maximum area of quadrilateral ABCDABCD is _____.

Problem 101

Given that the area of triangle ABC\mathrm{ABC} is 1, and BC=1\mathrm{BC}=1, when the product of the three altitudes of this triangle is maximized, sin⁡A=\sin A =

Problem 102

If each face of a tetrahedron is not an isosceles triangle, then it has at least_____ distinct edge lengths.

Problem 103

In tetrahedron ABCDABCD, where AC=15AC=15, BD=18BD=18, EE is the trisect point of ADAD closer to AA, FF is the trisect point of BCBC closer to CC, and EF=14EF=14. Then, the cosine value of the angle between edges ACAC and BDBD is_____.

Problem 104

Given that each face of the tetrahedron has edges of lengths 2\sqrt{2}, 3\sqrt{3}, and 22, the volume of this tetrahedron is _____.

Problem 105

Given that the line ll intersects two parabolas Γ1:y2=2px(p>0)\Gamma_{1}: y^{2}=2px (p>0) and Γ2:y2=4px\Gamma_{2}: y^{2}=4px at four distinct points A(x1,y1)A\left(x_{1}, y_{1}\right), B(x2,y2)B\left(x_{2}, y_{2}\right), D(x3,y3)D\left(x_{3}, y_{3}\right), and E(x4,y4)E\left(x_{4}, y_{4}\right), where y4<y2<y1<y3y_{4}<y_{2}<y_{1}<y_{3}. Let ll intersect the xx-axis at point MM. Given that AD=6BEAD = 6 BE, then the value of AMME\frac{AM}{ME} is _____.

Problem 106

Given that △ABC\triangle ABC is an acute-angled triangle, with AA, BB, and CC as its internal angles, the minimum value of 2cot⁡A+3cot⁡B+4cot⁡C2 \cot A+3 \cot B+4 \cot C is _____.

Problem 107

There are 10 points in the plane, with no three points lying on the same line. Using these 10 points as vertices of triangles, such that any two triangles have at most one common vertex, we can form at most _____ triangles.

Problem 108

Given that quadrilateral ABCDABCD is a parallelogram, with the lengths of ABAB, ACAC, ADAD, and BDBD being distinct integers, then the minimum perimeter of quadrilateral ABCDABCD is _____.

Problem 109

When the two ends of a strip of paper are glued together, forming a loop, it is called a circular ring. Cutting along the bisector of the paper strip will result in two circular rings. When a strip of paper is twisted 180 degrees and then the ends are glued together again, forming a loop, it is called a Mobius strip. Cutting along the bisector of the Mobius strip will result in a longer loop-like structure. If cut along the bisector of this longer loop-like structure, it will yield _____ loop-like structure again.

Problem 110

In the Cartesian coordinate system xOy, let Γ1\Gamma_{1} be the ellipse x2a2+y2b2=1(a>b>0)\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1(a>b>0) and Γ2\Gamma_{2} be the parabola y2=12axy^{2}=\frac{1}{2}ax. They intersect at points A and B, and P is the rightmost point of Γ1\Gamma_{1}. If points O, A, P, and B are concyclic, then the eccentricity of Γ1\Gamma_{1} is_____.

Problem 111

Given the circle Γ:x2+y2=1\Gamma: x^{2}+y^{2}=1, points A and B are two points symmetric about the x-axis on the circle. M is any point on the circle Γ\Gamma distinct from A and B. If MA and MB intersect the x-axis at points P and Q respectively, then the product of the abscissas of P and Q is _____.

Problem 112

If three points are randomly chosen from the vertices of a regular 17-sided polygon, what is the probability that the chosen points form an acute-angled triangle?

Problem 113

A rook piece moves through each square of a 2023×20232023\times 2023 grid paper once, each time moving only one square (i.e., from the current square to an adjacent square). If the squares are numbered from 1 to n2n^2 according to the order in which the rook piece reaches them, let M denote the maximum difference in numbers between adjacent squares. Then the minimum possible value of MM is?

Problem 114

Using the 24-hour clock, the probability of the sum of four digits at a certain moment being smaller than the sum of the four digits at 20:21 is _____.

Problem 115

A six-digit number N=a1a2...a6‾N=\overline{a_1a_2...a_{6}} composed of non-repeating digits from 1 to 6 satisfies the condition ∣ak+1−ak∣≠1,(k∈{1,2,⋯ ,5})|a_{k+1}-a_{k}| \neq 1, (k\in \{1,2, \cdots, 5\}). Then the number of such six-digit numbers is _____.

Problem 116

Given M={1,2,…,8},A,BM=\{1,2, \ldots, 8\}, A, B are two distincet subsets of set MM, satisfying

(1) The number of elements in set AA is fewer than the number of elements in set BB.

(2) The smallest element in set AA is larger than the largest element in set BB.

Then the total number of ordered pairs (A,B)(A, B) satisfying these conditions is _____.

Problem 117

Using six different colors to color each edge of the regular tetrahedron ABCDABCD, each edge can only be colored with one color and edges sharing a vertex cannot have the same color. The probability that all edges have different colors is _____.

Problem 118

The king summons two wizards into the palace. He demands Wizard A to write down 100 positive real numbers on cards (allowing duplicates) without revealing them to Wizard B. Then, Wizard B must accurately write down all of these 100 positive real numbers. Otherwise, both wizards will be beheaded. Wizard A is allowed to provide a sequence of numbers to Wizard B, where each number is either one of the 100 positive real numbers or a sum of some of them. However, he cannot tell Wizard B which are the numbers on the cards and which are the sums of numbers on the cards. Ultimately, the king decides to pull off the same number of beards from both wizards based on the count of these numbers. Without the ability to communicate beforehand, the question is: How many beard pulls does each wizard need to endure at least to ensure their own survival?

Problem 119

Using 1×11 \times 1, 2×22 \times 2, and 3×33 \times 3 tiles to cover a 23×2323 \times 23 floor (without overlapping or leaving gaps), what is the minimum number of 1×11 \times 1 tiles needed? (Assuming each tile cannot be divided into smaller tiles).

Problem 120

In a number-guessing game, the host has prearranged a permutation of the numbers 1 to 100, and participants also need to provide a permutation of these 100 numbers. Interestingly, as long as the permutation provided by a participant has at least one number whose position matches that of the host's permutation, it is considered a successful guess. How many participants are needed to ensure that at least one person guesses correctly?

Problem 121

There is a stack of 52 face-down playing cards on the table. Mim takes 7 cards from the top of this stack, flips them over, and puts them back at the bottom, calling it one operation. The question is: how many operations are needed at least to make all the playing cards face-down again?

Problem 122

There are two segments of length 3n(0≤n≤1011)3n (0 \leq n \leq 1011). How many different shapes of triangles can be formed from these 2024 segments? (Congruent triangles are considered the same.)

Problem 123

Let AA and BB be two subsets of the set {1,2,…,20}\{1,2, \ldots, 20\}, where A∩B=∅A \cap B = \varnothing, and if n∈An \in A, then 2n+2∈B2n + 2 \in B. Let M(A)M(A) denote the sum of the elements of AA. The maximum value of M(A)M(A) is:

Problem 124

Alice and Bob are playing a game. They write down four expressions on four cards: x+yx+y, x−yx-y, x2+xy+y2x^2+xy+y^2, and x2−xy+y2x^2-xy+y^2. They place these four cards face down on the table, then randomly choose one card to reveal its expression. Alice can pick two of the four cards and hand the other two to Bob, then all four cards are revealed. Alice can assign a value (real number) to one of the variables xx or yy and inform Bob of which variable she has assigned and what value. Afterwards, Bob assigns a value (real number) to the other variable. Finally, they each calculate the product of the values on their two cards, and the person with the larger product wins. Who has a winning strategy? A. Alice B. Bob C. Neither of them has a winning strategy.

Problem 125

Find the smallest integer k>2k > 2 such that any partition of {2,3,…,k}\{2,3,\ldots,k\} into two sets must contain at least one set containing aa, bb, and cc (which are allowed to be the same), satisfying ab=cab=c.

Problem 126

On a plane, there are 2019 points. Drawing circles passing through these points, a drawing method is called "kk-good" if and only if drawing kk circles divides the plane into several closed shapes, and there is no closed shape containing two points. Then, find the minimum value of kk , it ensures that no matter how these 2019 points are arranged, there always exists a kk-good drawing method.

Problem 127

Zheng flips an unfair coin 5 times. If the probability of getting exactly 1 head is equal to the probability of getting exactly 2 heads and is nonzero, then the probability of getting exactly 3 heads is ____.

Problem 128

Let a1,a2,…,a6a_{1}, a_{2}, \ldots, a_{6} be any permutation of {1,2,…,6}\{1,2, \ldots, 6\}. If the sum of any three consecutive numbers cannot be divided by 3, then the number of such permutations is _____.

Problem 129

Given an integer n>2n > 2. Now, there are nn people playing a game of "Passing Numbers". It is known that some people are friends (friendship is mutual), and each person has at least one friend. The rules of the game are as follows: each person first writes down a positive real number, and the nn positive real numbers written by everyone are all different; then, for each person, if he has kk friends, he divides the number he wrote by kk, and tells all his friends the result obtained; finally, each person writes down the sum of all the numbers he hears. The question is: what is the minimum number of times that someone writes down different numbers?

Problem 130

A restaurant can offer 9 types of appetizers, 9 types of main courses, 9 types of desserts, and 9 types of wines. A company is having a dinner party at this restaurant, and each guest can choose one appetizer, one main course, one dessert, and one type of wine. It is known that any two people's choices of the four dishes are not completely identical, and it is also impossible to find four people on the spot who have three identical choices but differ pairwise in the fourth choice (for example, there are no 9 people who have the same appetizer, main course, and dessert, but differ pairwise in the wine). Then, at most how many guests can there be?

Problem 131

Alice and Bob are playing hide-and-seek. Initially, Bob selects a point BB inside a unit square (without informing Alice). Then, Alice sequentially selects points P0,P1,…,PnP_0, P_1, \ldots, P_n on the plane. After each selection of a point Pk(1≤k≤nP_k (1 \leq k \leq n, and at this point, Alice has not yet chosen the next point), Bob informs Alice which of the points PkP_k and Pk−1P_{k-1} is closer to point BB. After Alice selects PnP_n and receives Bob's response, she chooses a final point AA. If the distance between AA and BB does not exceed 12020\frac{1}{2020}, Alice wins. Otherwise, Bob wins. When n=18n=18, which of the following options is correct? A. Alice cannot guarantee victory. B. Alice can guarantee victory.

Problem 132

Anna, Carl take turns selecting numbers from the set {1,2,⋯ ,p−1}\{1,2, \cdots, p-1\} (where pp is a prime greater than 3). Anna goes first, and each number can only be selected once. Each number chosen by Anna is multiplied by the number Carl selects next. Carl wins if, after any round, the sum of all products computed so far is divisible by pp. Anna wins if, after all numbers are chosen, Carl has not won. Which of the following options is correct?

A. Anna has a winning strategy. B. Carl has a winning strategy. C. Both players have no winning strategy.

Problem 133

Xiao Ming is playing a coin game with three doors. Each time he opens a door, it costs him 2 coins. After opening the first door, he can see the second door. Upon opening the second door, two equally likely options appear: either return to the outside of the first door or proceed to the third door. Upon opening the third door, three equally likely options appear: either return to the outside of the first door, stay in place and need to reopen the third door, or pass the game. If Xiao Ming wants to pass the game, on average, he needs to spend how many coins?

Problem 134

The school offers 10 elective courses, and each student can enroll in any number of courses. The director selects kk students, where although each student's combination of courses is different, any two students have at least one course in common. At this point, it is found that any student outside these kk students cannot be classmates with these kk students regardless of how they enroll (having one course in common is enough to be classmates). Then k=k= _____.

Problem 135

Let nn be a positive integer. Now, a frog starts jumping from the origin of the number line and makes 2n−12^{n}-1 jumps. The process satisfies the following conditions:

(1) The frog will jump to each point in the set {1,2,3,⋯ ,2n−1}\left\{1,2,3, \cdots, 2^{n}-1\right\} exactly once, without missing any.

(2) Each time the frog jumps, it can choose a step length from the set {20,21,22,⋯ }\left\{2^{0}, 2^{1}, 2^{2}, \cdots\right\}, and it can jump either left or right.

Let TT be the reciprocal sum of the step lengths of the frog. When n=2024n=2024, the minimum value of TT is _____.

Problem 136

Given that there are 66 dwarves with a total of 111 hats, each hat belonging to a specific dwarf, and each hat is dyed in one of 66 colors. During the holiday, each dwarf wears his own hat. It is known that for any holiday, the colors of the hats worn by all dwarves are different. For any two holidays, there is at least one dwarf who wears hats of different colors on the two occasions. The question is: how many holidays can the dwarves celebrate at most?

Problem 137

There are nn cards, each labeled with the numbers 1,2,⋯ ,n1 , 2, \cdots, n. These nn cards are distributed among 17 people, with each person receiving at least 1 card. Then, there is always one person who receives cards with numbers xx and yy, where x>yx>y, and 118x⩽119y118x \leqslant 119y. The smallest positive integer nn that satisfies this condition is _____.

Problem 138

let a1,a2,⋯ ,a9a_{1}, a_{2}, \cdots, a_{9} be a permutation of 1,2,⋯ ,91,2, \cdots, 9. If the permutation C=(a1,a2,⋯ ,a9)C=\left(a_{1}, a_{2}, \cdots, a_{9}\right) can be obtained from 1,2,⋯ ,91,2, \cdots, 9, by swapping two elements at most 4 times, the total number of permutations satisfying this condition is _____.

Problem 139

Let sequence a1,a2,⋯ ,a10a_{1}, a_{2}, \cdots, a_{10} satisfy 1⩽a1⩽la2⩽⋯⩽a10⩽401 \leqslant a_{1} \leqslant{l} a_{2} \leqslant \cdots \leqslant a_{10} \leqslant 40, a4⩾6a_{4} \geqslant6, and log⁡2(∣ai−i∣+1)∈N(i=1,2,⋯ ,10)\log _{2}\left(\left|a_{i}-i\right|+1\right) \in \mathbf{N}(i=1,2, \cdots, 10) The number of such sequences is _____.

Problem 140

A student walks through a hallway with a row of closed lockers numbered from 1 to 1024. He starts by opening locker number 1, then proceeds forward, alternately leaving untouched or opening one closed locker. When he reaches the end of the hallway, he turns around and walks back, opening the first closed locker he encounters. The student continues this back and forth journey until every locker is opened. The number of the last locker he opens is _____.

Problem 141

Let A={−3,−2,⋯ ,4},a,b,c∈AA=\{-3,-2, \cdots, 4\}, a, b, c \in A be distinct elements of A. If the angle of inclination of the line: ax+by+c=0a x+b y+c=0 is acute, then the number of such distinct lines is _____.

Problem 142

In a sequence of length 15 consisting of aa and bb, if exactly five "aa"s occur and both "ab" and "ba" and "bb" occur exactly three times, there are _____ such sequences.

Problem 143

Among the five-digit numbers formed by the digits 1, 2, ..., 6, the number of five-digit numbers satisfying the condition of having at least three different digits and 1 and 6 not being adjacent is _____.

Problem 144

How many numbers can be selected at most from 1 to 100 to ensure that the quotient of the least common multiple and greatest common divisor of any two numbers is not a perfect square?

Problem 145

From the natural numbers 1 to 100, choose any mm numbers such that among these mm numbers, there exists one number that can divide the product of the remaining m−1m-1 numbers. The minimum value of mm is _____.

Problem 146

Several teams are participating in a friendly football match, where any two teams play at most one match against each other. It is known that each team has played 4 matches, and there are no draws. A team is considered a "weak team" if it loses at least 2 out of the 4 matches it plays. If there are only 3 "weak teams" in this friendly match, then at most how many teams could have participated in the matches?

Problem 147

In the equation, the same letter represents the same digit, and different letters represent different digits. Then, the four-digit number abcd‾\overline{a b c d} is given by:

(ab‾)c×acd‾=abcacd‾(\overline{a b})^{c} \times \overline{a c d}=\overline{a b c a c d}

Problem 148

Let nn be represented as the difference of squares of two nonzero natural numbers, then there are F(n)F(n) ways to do so.

For example, 15=82−72=42−1215=8^{2}-7^{2}=4^{2}-1^{2}, so F(15)=2F(15)=2; whereas 2 cannot be represented, hence F(2)=0F(2)=0. Then, the calculation result of F(1)+F(2)+F(3)+⋯+F(100)F(1)+F(2)+F(3)+\cdots+F(100) is _____.