Maths Olympiad Prep

Library / /5 of 16

, 2021

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

In the four-digit number 4753, three two-digit numbers are formed by successive pairs of digits (47, 75, 53). Exactly two of these two-digit numbers are prime. Find all four-digit numbers in which all four digits are prime, and all three two-digit numbers formed by successive digits are prime.

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.