1. Write a recursive method that displays a given message n times.
2. Define a recursive method f that, given a nonnegative integer n, returns n % 2 when n ranges from 0 to 9 f(n / 10) + (n % 10) % 2 when n is greater than or equal to 10
3. Jack and Jill take turns using a one-gallon pail to empty a tank of water. On his turn, Jack always removes one gallon of water. Jill, however, removes one or two gallons so that either an even number of gallons are left in the tank or the tank becomes empty. Using recursion, how many turns in total must Jack and Jill make to empty the tank, if it initially contains n gallons? Write a recursive method that counts and returns the total number of turns given the number of gallons n.