Problem 1/1. For every positive integer n, form the number n/s(n), where s(n) is the sum of the digits of n in base 10. Determine the minimum value of n/s(n) in each of the following cases:
(i) 10 ≤ n ≤ 99
(ii) (ii) 100 ≤ n ≤ 999
(iii) 1000 ≤ n ≤ 9999
(iv) 10000 ≤ n ≤ 99999
Problem 2/1. Find all pairs of integers, n and k, 2 < k < n, such that the binomial coefficients
form an increasing arithmetic series.
Problem 3/1. On an 8 x 8 board we place n dominoes, each covering two adjacent squares, so that no more dominoes can be placed on the remaining squares. What is the smallest value of n for which the above statement is true?
Problem 4/1. Show that an arbitrary acute triangle can be dissected by straight line segments into three parts in three different ways so that each part has a line of symmetry.
Problem 5/1. Show that it is possible to dissect an arbitrary tetrahedron into six parts by planes or portions thereof so that each of the parts has a plane of symmetry.
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