Since he charged $65 for the parts, and the total charge was $110, that's $110-$65 which is $45, the total hours was 3, so $45 divided by 3, and that equals $15.
Her box is 12 inches tall. -Because if you multiply 13 × 5, you get 65 (this is the base) then you work backwards and divide 780 by 65 (780 ÷ 65). Therefore your answer is 12 inches