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?

1 Answer
Aug 7, 2018

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


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%#