Maths Olympiad Prep

Library / /64 of 99

, 2025

Number theory Difficulty 3.0 AMC 10/12 Prove it United Kingdom

Kitty claims that for every positive integer nn, the product (5n+1)(6n1)(n32)(5n + 1)(6n - 1)(n^3 - 2) is not divisible by 77. What is the smallest three-digit value of nn which is a counterexample to Kitty's claim?

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: UK Mathematics Trust, licensed © UK Mathematics Trust; past papers published free at ukmt.org.uk. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.