A game is played by choosing 2 cards randomly from a deck of cards.

I am going to work this out assuming that Im working with the following; King, Queen, Jack, 10, 9, 8, 7, 6, 5, 4, 3, 2, and Ace

Thats 13 cards per suit; Diamonds, Spades, Clubs and Hearts

a total of 52 cards

First lets calculate the probability of drawing two consecutive cards from one suite;

you win only if the two cards are consecutive;

= 13(c2) = 13 x 12 / 2 = 78

so ...no of ways this can happen is ( n -1 ) = 13- 1 = 12

probability for win = 12 /78 per suit

For 100 games number of wins;

= 100 x 12 / 78 = $15.38 x 2$ per win = $30.76

to get the probability of the deck divide by 4

$30.76 / 4 = $7.69

Hope this helps