Answer:
- 10 quarters
- 20 dimes
- 18 nickels
Explanation:
If we add 2 nickels to Sam's coin collection, we can group the coins into groups that contain 1 quarter, 2 dimes, and 2 nickels. Each group is worth $0.55, and all of the coins together will be worth $5.50.
That is, there are $5.50/$0.55 = 10 groups of coins.
Sam has 10 quarters, 20 dimes, and two fewer nickels than 20, so 18 nickels.