In mod n arithmetic, the quotient of two numbers r and m is a number q such that mq = r mod n. (a) Given r, m, and n, how can one find q? (b) How many qs are there? (c) Under what conditions is q unique? (Hint: mq = r mod n iff there is an integer k such that qm + kn = r. Divide by gcd(m, n).)