Question

Two coins are taken at random from a bank containing 4 dimes, 8 quarters, and 3 nickels. What is the probability that both coins will be quarters?

Answer 1

`8/30` OR `26.bar6%`

Explanation:

There are a total of 15 coins, so there is an 8 in 15 chance of getting one-quarter. This can be expressed as `8/15`.

Now supposed you do get the quarter the first time. Now there are only 7 quarters left in the bank, and only 14 coins that can be possibly picked. The probability now is `7/14` or `1/2`.

Because picking two coins without replacing them are dependant on which ones you choose, you have to multiply the probabilities.

`8/15*1/2=8/30`