A website says that you'll need 48 fifty-pound bags of sand to fill a sandbox that measures 8 ft by 8 ft by 1 ft. How many bags would you need for sandbox 6 ft by 4 ft by 1 ft?
8 x 8 x 1 = 64 ft^3
6 x 4 x 1 = 24 ft^3
So....we have this proportion
48 / 64 = x / 24 where x is the number of bags we need
3 / 4 = x /24 multiply both sides by 24
18 = x
We need 18 bags
