Maths Olympiad Prep

Library / /62 of 146

, 2016

Number theory Difficulty 2.0 Junior Find the answer United Kingdom

Let nn be the smallest integer for which 7n7n has 2016 digits. What is the units digit of nn?

(A) 00 (B) 11 (C) 44 (D) 66 (E) 88

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.