MathDB
2018 COMC B4

Source:

December 6, 2018
Comc2018 COMC

Problem Statement

Source: 2018 Canadian Open Math Challenge Part B Problem 4 —--
Determine the number of 55-tuples of integers (x1,x2,x3,x4,x5)(x_1,x_2,x_3,x_4,x_5) such that (a)\text{(a)} xiix_i\ge i for 1i51\le i \le 5; (b)\text{(b)} i=15xi=25\sum_{i=1}^5 x_i = 25.