Answer:
I am expected to win $150
Step-by-step explanation:
We need to calculate the probability of drawing 2 black cards with replacement
There are 26 black cards in a deck of cards
The probability of drawing a black card is thus 26/52 = 1/2
So the probability of drawing two black cards in succession with replacement will be 1/2 * 1/2 = 1/4
So the probability of not drawing the two in succession will be 1 - 1/4 = 3/4
so out of twenty trials the number of times the drawing will occur will be 1/4 * 20 = 5 times
The number of times it will not occur will be 20-5 = 15 times
The amount my friend will win will be 5 * 30 = 150
The amount I will win will be 20 * 15 = 300
The amount I expect to win in the deal will be 300-150 = $150