Latest Maths Olympiad Aptitude Question SOLUTION: Suppose the integers 1, 2, 3, . . . , 10 are split into two disjoint collections a1, a2, a3, a4, a5 and b1, b2, b3, b4, b5 such that a1 < a2 < a3 < a4 < a5, b1 > b2 > b3 > b4 > b5.