Question

You reach into a bag of coins and withdraw two coins. What is the probability you a nickel and then a dime if the bag held five pennies, ten nickels, and four dimes?

Answer 1

`11.696%` (if you withdraw one after the first one without putting it back).

Explanation:

There are 19 coins (5 pennies, 10 nickels, and 4 dimes).

You withdraw one coin and it is a nickel (`p=10/19`).

You withdraw another one and it is a dime (`p=4/18`) because you do not put the first coin back into the bag.

The probability of this outcome is: `p=(10/19)times(4/18) = 40/342 = 11.696%`

If you put the coin back after the first withdraw, the probability is different:

`p=(10/19)times(4/19) = 40/361 = 11.08%`