Need help please!!

Question

A number of softwood 2 x 4 boards are to be placed in a rectangular stack.

A softwood 2 x 4 board is actually 1 1/2 in 3 1/2 in. Recall that the smaller dimensions are due to planing and shringkage of roughly cut 2 in x 4 in board that takes place at sawmills.

The reclangular stack of 2 x 4 board is to be 21 in wide and 12 in high.

Calculate how many 2 x 4 board would be in this stack. Hint: The board are laid flat with the 3 1/2 -in side down.

Answer 1

A bunch of 2 x 4 softwood boards are to be placed in a rectangular stack.

A softwood 2 x 4 board is cut down to .

The reclangular stack of 2 x 4 board is to be 21 in wide and 12 in high.

Thus, area of the each softwoodboard is  square inches.

Let the number of boards are placed inside rectangular stack is .

Area of the rectangular stack is  square inches.

Therefore, 

Thus, the number of softwood boards inside the rectangular stack are 48.