Library / /92 of 149

, 2022

Number theory Difficulty 2.0 Junior Find the answer United Kingdom

The positive integer 1 and every fourth integer after that are coloured red; 2 and every fourth integer after that are coloured blue; 3 and every fourth integer are coloured yellow and 4 and every fourth integer are coloured green. Peter picks a number coloured yellow and a number coloured blue and adds them together. What could the colour of his answer be?

(A) blue or green (B) only green (C) only yellow (D) only blue (E) only red

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.