posted by sheryl on .
Gary has 10 coins in his pocket.
without looking, Gary pulls 1 coin from
his pocket and puts it on a table. Then,
he pulls one more coin from his pocket.
What is the probability that the first
coin is a dime and the second coin is a
At the beginning, he had 10 coins and drew one. For this one to be a dime, it has a probability of 5/10 (5 dimes out of 10 coins in total).
Then, after drawing that coin, he has 9 total coins in his pocket, then he drew one. For this coin to be a nickle, it has a probability of 3/9 (3 nickels out of 9 total coins).
Pro(dime) = 5/10
Without replacement total left= 9
Thus prob(nickel) = 3/9