Deval has a rectangular patio that is 15 feet long and 5 feet wide. if Deval uses square tiles with a side length of 1 foot, how many tiles will he need to cover the patio?

Find the area of the rectangular patio.

A = lw

A = 15 * 5

A = 75

Now find the area of each square tile:

A = s^2

A = 1^2

A = 1

Divide this by 75:

75 / 1 = 75

So he needs 75 square tiles to cover the patio.