You decide to offer a gambling game with cards to your friend, Amos. You mark each card with a number from 1 to 52 ; that is, you write 1 on the first card in the deck, 2 on the second card, etc., to 52 on the last card. You shuffle the cards. If the top four cards are in ascending order you pay Amos $$\$ 20$$; otherwise he pays you a dollar. (By ascending order we mean, for example, the top card is 7 , the second card 12 , the third card is 40 , and the fourth card is 47. .) What is the probability that Amos will win? What is your average winning per play? [Hint: In how many orders can the top 4 cards be arranged?]