olymmath

CONO-SUR 1996

Cono Sur Mathematical Olympiad 1996.

Other problems

Problem 1

In the following figure, the largest square is divided into two squares and three rectangles, as shown:

The area of each smaller square is equal to aa and the area of each small rectangle is equal to bb . If a+b=24a+b=24 and the root square of aa is a natural number, find all possible values for the area of the largest square. Image

Problem 2

Consider a sequence of real numbers defined by: an+1=an+1ana_{n + 1} = a_n + \frac{1}{a_n} for n=0,1,2,...n = 0, 1, 2, ... Prove that, for any positive real number a0a_0 , is true that a1996a_{1996} is greater than 6363 .

Problem 3

A shop sells bottles with this capacity: 1L,2L,3L,...,1996L1L, 2L, 3L,..., 1996L , the prices of bottles satifies this 22 conditions: 11 . Two bottles have the same price, if and only if, your capacities satifies m−n=1000m - n = 1000 22 . The price of bottle mm ( 1001>m>01001>m>0 ) is 1996−m1996 - m dollars. Find all pair(s) mm and nn such that: a) m+n=1000m + n = 1000 b) the cost is smallest possible!!! c) with the pair, the shop can measure kk liters, with 0<k<19960<k<1996 (for all kk integer) Note: The operations to measure are: i) To fill or empty any one of two bottles ii)Pass water of a bottle for other bottle We can measure kk liters when the capacity of one bottle plus the capacity of other bottle is equal to kk

Problem 4

The sequence 0,1,1,1,1,1,....,10, 1, 1, 1, 1, 1,....,1 where have 11 number zero and 19951995 numbers one. If we choose two or more numbers in this sequence(but not the all 19961996 numbers) and substitute one number by arithmetic mean of the numbers selected, we obtain a new sequence with 19961996 numbers!!! Show that, we can repeat this operation until we have all 19961996 numbers are equal Note: It's not necessary to choose the same quantity of numbers in each operation!!!

Problem 5

We want to cover totally a square(side is equal to kk integer and k>1k>1 ) with this rectangles: 11 rectangle ( 1×11\times 1 ), 22 rectangles ( 2×12\times 1 ), 44 rectangles ( 3×13\times 1 ),...., 2n2^n rectangles ( n+1×1n + 1 \times 1 ), such that the rectangles can't overlap and don't exceed the limits of square. Find all kk , such that this is possible and for each kk found you have to draw a solution

Problem 6

Find all integers n≤3n \leq 3 such that there is a set SnS_n formed by nn points of the plane that satisfy the following two conditions: Any three points are not collinear. No point is found inside the circle whose diameter has ends at any two points of SnS_n .NOTE: The points on the circumference are not considered to be inside the circle.