1. Prove the following statements using a direct proof, a proof by contrapositive, a proof by contradiction, or a proof by cases. a. For any integer n, if 5n 3 is even, then n is odd. b. If two integers have opposite parity, then their product is even. c. If you pick four individual socks from a drawer containing white socks, blue socks and black socks, you must get at least one pair of white socks, blue socks or black socks