A box 3" wide and 2" deep is to have a volume of 2 cubic feet. How long must the box be?

How many pieces of lumber are stacked in a pile 2" high if each board is 3/8" thick?

Hi,

The volume of a rectangular box is given by

volume = length x width x depth

You have a volume of 2 cubic feet which is 2 x 12 x 12 x 12 =3456 cubic inches, a width of 3 inches and a depth of 2 inches. Thus

3456 = length x 3 x 2

Find the length.

For the second problem the height of the pile in inches is

3/8 x (number of boards)

I think that the problem should say that the height of the pile is 2 feet, which is 24 inches. Thus you have

24 = 3/8 x (number of boards)

What is the number of boards?

Cheers,
Penny
Go to Math Central