Hi,
18" 18" 24" = 7776 inches inches inches = 7776 cubic inches. But you want cubic feet so you should change the dimensions to feet. There are 12 inches in a foot so
18 inches = ^{18}/_{12} = 1.5 feet and
24 inches = ^{24}/_{12} = 2 feet
Thus the vulume is
1.5 1.5 2 = 4.5 cubic feet.
Penny
