Brendan has 33 coins in his pocket, all of which are dimes and quarters. if the total value of his change is 615 cents, how many dimes and how many quarters does he have?
If all were dimes, the value would be $3.30. Brendan has $2.85 more than that. Each quarter that replaces a dime increases the value by $0.15, so Brendan must have $2.85/$0.15 = 19 quarters.
