Question

Adam has 4 dimes, 4 quarters and 4 nickels in his pocket. He pulls out 2 coins making sure to put the first one back in his pocket before picking the second. What are the odds that he pulls out 2 nickels?

Answer 1

SInce he puts the first one back, the two events are independent of one another. So, the probability is the P(nickel)*P(nickel), where P(nickel) is the probability of pulling out one nickel. P(nickel)=number of nickels/total number of coins

Answer 2

so what's the probability? 1/3, 1/16, 1/9 or 1/81?

Answer 3

You have to multiply P(getting one nickel)*P(getting one nickel) where P(getting one nickel) = (4 nickels)/(4 nickels+4 dimes +4 quarters)