Let be a prime number. Show that there is a permutation of so that leave distinct remainders when divided by .
Solution
By the Chinese remainder Theorem, for every there exists so that
Let and for , is the remainder when is divided by . Since , we have . Also if , then , i.e., . Since is prime, . Thus are distinct. Now
Want a route through all this instead of an archive? The track
puts 2,000 problems in a working order, from AMC 10 level to the IMO shortlist.