olymmath

AIME 2003a

American Invitational Mathematics Examination 2003.

Paper

Problem 2

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One hundred concentric circles with radii 1,2,3,…,1001, 2, 3, \dots, 100 are drawn in a plane. The interior of the circle of radius 11 is colored red, and each region bounded by consecutive circles is colored either red or green, with no two adjacent regions the same color. The ratio of the total area of the green regions to the area of the circle of radius 100100 can be expressed as m/n,m/n, where mm and nn are relatively prime positive integers. Find m+n.m + n.

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Problem 3

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Let the set S={8,5,1,13,34,3,21,2}.\mathcal{S} = \{8, 5, 1, 13, 34, 3, 21, 2\}. Susan makes a list as follows: for each two-element subset of S,\mathcal{S}, she writes on her list the greater of the set's two elements. Find the sum of the numbers on the list.

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Problem 4

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Given that log⁡10sin⁡x+log⁡10cos⁡x=−1\log_{10} \sin x + \log_{10} \cos x = -1 and that log⁡10(sin⁡x+cos⁡x)=12(log⁡10n−1),\log_{10} (\sin x + \cos x) = \frac{1}{2} (\log_{10} n - 1), find n.n.

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Problem 5

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Consider the set of points that are inside or within one unit of a rectangular parallelepiped (box) that measures 33 by 44 by 55 units. Given that the volume of this set is m+nπp,\frac{m + n\pi}{p}, where m,n,m, n, and pp are positive integers, and nn and pp are relatively prime, find m+n+p.m + n + p.

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Problem 6

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The sum of the areas of all triangles whose vertices are also vertices of a 11 by 11 by 11 cube is m+n+p,m + \sqrt{n} + \sqrt{p}, where m,n,m, n, and pp are integers. Find m+n+p.m + n + p.

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Problem 7

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Point BB is on AC‾\overline{AC} with AB=9AB = 9 and BC=21.BC = 21. Point DD is not on AC‾\overline{AC} so that AD=CD,AD = CD, and ADAD and BDBD are integers. Let ss be the sum of all possible perimeters of △ACD\triangle ACD. Find s.s.

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Problem 8

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In an increasing sequence of four positive integers, the first three terms form an arithmetic progression, the last three terms form a geometric progression, and the first and fourth terms differ by 3030. Find the sum of the four terms.

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Problem 9

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An integer between 10001000 and 99999999, inclusive, is called balanced if the sum of its two leftmost digits equals the sum of its two rightmost digits. How many balanced integers are there?

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Problem 10

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Triangle ABCABC is isosceles with AC=BCAC = BC and ∠ACB=106∘.\angle ACB = 106^\circ. Point MM is in the interior of the triangle so that ∠MAC=7∘\angle MAC = 7^\circ and ∠MCA=23∘.\angle MCA = 23^\circ. Find the number of degrees in ∠CMB.\angle CMB.

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Problem 11

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An angle xx is chosen at random from the interval 0∘<x<90∘.0^\circ < x < 90^\circ. Let pp be the probability that the numbers sin⁡2x,cos⁡2x,\sin^2 x, \cos^2 x, and sin⁡xcos⁡x\sin x \cos x are not the lengths of the sides of a triangle. Given that p=d/n,p = d/n, where dd is the number of degrees in arctan\text{arctan} mm and mm and nn are positive integers with m+n<1000,m + n < 1000, find m+n.m + n.

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Problem 12

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In convex quadrilateral ABCD,∠A≅∠C,AB=CD=180,ABCD, \angle A \cong \angle C, AB = CD = 180, and AD≠BC.AD \neq BC. The perimeter of ABCDABCD is 640640. Find ⌊1000cos⁡A⌋.\lfloor 1000 \cos A \rfloor. (The notation ⌊x⌋\lfloor x \rfloor means the greatest integer that is less than or equal to x.x.)

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Problem 13

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Let NN be the number of positive integers that are less than or equal to 20032003 and whose base-22 representation has more 11's than 00's. Find the remainder when NN is divided by 10001000.

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Problem 14

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The decimal representation of m/n,m/n, where mm and nn are relatively prime positive integers and m<n,m < n, contains the digits 2,52, 5, and 11 consecutively and in that order. Find the smallest value of nn for which this is possible.

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Problem 15

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In △ABC,AB=360,BC=507,\triangle ABC, AB = 360, BC = 507, and CA=780.CA = 780. Let MM be the midpoint of CA‾,\overline{CA}, and let DD be the point on CA‾\overline{CA} such that BD‾\overline{BD} bisects angle ABC.ABC. Let FF be the point on BC‾\overline{BC} such that DF‾⊥BD‾.\overline{DF} \perp \overline{BD}. Suppose that DF‾\overline{DF} meets BM‾\overline{BM} at E.E. The ratio DE:EFDE: EF can be written in the form m/n,m/n, where mm and nn are relatively prime positive integers. Find m+n.m + n.

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