The equation for this problem would be A=C^2 divided by 4pi. Plugging in with the numbers it would be, 8pi^2 / 4pi. This then comes to the new equation 64pi / 4 pi when solving this it comes to the solution if 16 being the answer.
Answer: 16
The deck consists of 4 jacks, 26 black cards, and 13 hearts.
There is only 1 way of drawing all 4 jacks:
.
There are
ways of drawing 4 black cards.
There are
ways of drawing 4 hearts.
There are
ways of drawing any 4 cards.
The probabilities are then
a.

b.

c.

C,B,D,A
8/4= 2
4/3= 1 1/3
7/5 = 1 2/5
7/10 cant be simplfied at all