Assume that you select 4 coins at random from 7 coins: 5 dimes and 2 quarters. What is the probability that all of the coins selected are dimes? Enter your answer as a fraction

Question

Assume that you select 4 coins at random from 7 coins: 5 dimes and 2 quarters.

What is the probability that all of the coins selected are dimes? Enter your answer as a fraction

Answer 1

Kayla,

5 dimes and 2 quarters

total 7 coins

probability of selecting 1 dime is 5/7

probability of selecting 2 dimes is 5/7 * 4/6 = 20/42 = 10/21

probability of selecting 4 dimes is 5/7 * 4/6 * 3/5 * 2/4 = 120/840 = 1/7