A 15 1/2 foot board is cut into pieces 3 1/4 long for a bookcase. What is the length of the piece remaining after as many shelves as possible have been cut?

Answer 1

15.5 / 3.25 = 4.769 feet

0.769 * 12 = 9.228 inches

Answer 2

you cut four planks out of it
4*3.25 = 13 feet used
that leaves 2 1/2 feet