Thinking Cap

Problem of the Month

Winners of the academic year 2023/24 is Jacob Norris.

March 2025

March sequences

Suppose that kn is an infinite sequence of real numbers, indexed by the natural numbers, for which k1>1 and such that k1+k2+...+kn<2kn for every n. Show that there exists a real number q>1 having the property that qn < kn for all n.