How many tiles would I need?

Question

The wall has a dimension of 12ft x 9ft.

The door on the wall has a dimension of 3ft x 6ft.

Each tile is 4in x 6in.

How many tiles would I need to fill the wall (not including the door)?

Answer 1

12x9 = 108

3x6= 18

108-18 =90 square feet

each square foot = 12x12 = 144 inches

90 ft^2 = 90x144 = 12960 square inches

each tile is 4x6 = 24 square inches

12960/24 = 540 tiles