In single-deck casino blackjack, the dealer is dealt two cards from a standard deck of 52.

The first card is dealt face down and the second card is dealt face up.

a. How many dealer hands are possible if it matters which card is face down and which is face up?

b. How many dealer hands are possible if it doesn’t matter which card is face down and which is face up?

c. Of the 52 cards in the deck, four are aces and 16 others

(kings, queens, jacks, and tens) are worth 10 points each. The dealer has a blackjack if one card is an ace and the other is worth 10 points; it doesn’t matter which card is face up and which card is face down. How many different blackjack hands are there?

d. What is the probability that a hand is a blackjack?