Problem

Source: Singapore Open Math Olympiad 2017 2nd Round p4 SMO

Tags: algebra, inequalities, Arithmetic Progression, geometric progression, Sequences



Let $n > 3$ be an integer. Prove that there exist positive integers $x_1,..., x_n$ in geometric progression and positive integers $y_1,..., y_n$ in arithmetic progression such that $x_1<y_1<x_2<y_2<...<x_n<y_n$