Question

Heather and her friends are painting the walls of a storage room in the basement. Each wall is 9 m long and 2 m high. There are two doors, each 1 m wide and 2 m high. The doors are not being painted.

One litre of paint covers 10 m2. How many litres of paint will Heather need?

The price of the paint is $3.75/L. How much will the paint cost?​

Answer 1

• 7 L
• $26.25

Explanation:

The four walls have a linear length of (9 m)×4 = 36 m. Of that, the two 1-meter doors are not painted, so the linear length of the painted area is 34 m. The painted area is 2 m high, so the total area being painted is ...

A = LW

A = (34 m)(2 m) = 68 m²

The amount of paint needed for this area is ...

(68 m²) × (1 L/(10 m²) = 6.8 L

If we assume the paint only comes in units of 1 L, then Heather will need 7 L of paint.

The cost of 7 L of paint is ...

(7 L) × ($3.75/L) = $26.25

Heather will need 7 L of paint, for a total cost of $26.25.