$ 30 for 12 cans of tennis balls.....thats (30/12) = $ 2.50 per can
$ 45 for 2 boxes of golf balls....thats (45/2) = $ 22.50 per box
so if the coach ordered 100 cans of tennis balls and 5 boxes of golf balls, then he paid : (2.50 * 100) + (22.50 * 5) = 250 + 112.50 = $ 362.50 <=
