Number theoryDifficulty 2.0JuniorFind the answerUnited Kingdom
Let n be the smallest integer for which 7n has 2016 digits. What is the units digit of n?
(A) 0 (B) 1 (C) 4 (D) 6 (E) 8
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.