Two cards are a blackjack if one is an A and the other is a

Two cards are a blackjack if one is an A and the other is a K,Q,J or 10. (a) If you pick two cards out of a deck, what is the probability that you will get a blackjack? (b) Suppose you are playing blackjack against the dealer with a freshly shuffled deck. What is the probability that you or the dealer will get a blackjack?