Library / /24 of 121

, 2017

Number theory Difficulty 1.0 Junior Find the answer United Kingdom

Maria chooses two digits $a$ and $b$ and uses them to make a six-digit number $ababab$ . Which of the following is always a factor of numbers formed in this way?

(A) $2$ (B) $5$ (C) $7$ (D) $9$ (E) $11$

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.