Question

Lyana is painting her bedroom. Her room is 12’ x 18’. The ceilings are 8 feet high. She will need to put two coats of paint on. How many cans of paint will she need if the square footage of one can is 400 square feet?

Answer 1

Lyana will need 4 cans of paint to paint her whole room or only 3 if she doesn't paint the floor.

Explanation:

Firstly we need to know how much paint she will need to use.

The area of her room is given by 2(ac+bc), where a is the length, b is the width and c is the height.

Applying that we get that the area of her room is 2*12*18+2*18*8=720.

This applies if we assume that she also paints the floor. If she doesn't we need to subtract the area of the floor which is 12*18=216. So 720-216=504

She will paint her room twice she the amount of paint she needs is twice the area:

720*2=1440

or if she does not paint the floor

504*2=1008

Now we answer how many cans is that by dividing by 400 and rounding up.

1440/400=3.6 she needs, therefore, 4 cans

1008/400=2.52 she needs 3 cans

Answer 2

2 cans to cover the room but she will have a lot of paint left over

Explanation:

12*18=216

the area of her room is 216 square ft.

216*2=432

she will need 2 cans