Question

In a coin collection, the number of dimes is 10 less than three times the number of quarters. If the collection has 56 dimes, How many quarters are in the collection?

Answer 1

Quarters = x
Dimes = y

y = 3x - 10; Since the collection has 56 dimes:

56 = 3x - 10

Solve for x: 3x = 66 => x = 22

The number of quarters in the collection is 22.