500
Paul needs 8 pieces of lumber, each 38.5 inches long, to build a bookcase. The minimum # of 10-foot boards he needs to buys is:
What is 3.
(Each 10 foot board is 120 inches. 120/38.5= 3 and a remainder, so he can get 3 38.5 inch pieces from each 10 foot board. Since he needs 8 pieces, he'd have to buy 3 10 foot boards & he'd have some left over.)