Tom has 30 coins with a value of $3.30. If they are all nickels and quarters, how many of each kind of coin does he have?
q = quarters value = 25q
n = nickels = 30-q value = 5(30-q) summed they equal 330
25q + 5 (30-q) = 330 solve fo q the # quarters then nickels = 30-q