87 written as a fraction is
a.8/9
b.79/90
c.81/90

Probability breaks down to this basic formula:

    desired outcome    

total possible outcomes

Also, you need to know there are 13 spades in a deck of cards.

So, on your first draw, the chances of getting a spade are:

13    (desired outcome: pick one of the 13 spades)

52    (total possibilities: 52 cards in the deck)

But on your second draw, if you don't replace the card, your chances of getting a spade are:

12

51

because you only have 12 spades left, and 51 cards total.

Then, on your last draw, the chances of getting a spade are down to:

11

50

Since each of these probabilities depend on each other, you multiply them up to get your overall probability:

13 * 12 * 11 =   1,716

52    51    50    132,600

This reduces, or you can just divide to get a decimal.

Step-by-step explanation: