Question

arnie wants to paint 350 square metres of the outside walls of his house.

the undercoat he needs to buy comes in 4-litre cans.
one litre of undercoat covers 10 square metres.

how many cans does arnie need to buy for one undercoat?

8 cans
9 cans
35 cans
88 cans

Explanation:

Calculate total litres of undercoat needed

$$ \text{Total Litres} = \frac{350\text{ m}^2}{10\text{ m}^2/\text{litre}} = 35\text{ litres} $$

Calculate number of cans required

$$ \text{Number of Cans} = \frac{35\text{ litres}}{4\text{ litres/can}} = 8.75\text{ cans} $$

Round up to the nearest whole can

$$ \text{Cans to buy} = \lceil 8.75 ceil = 9\text{ cans} $$

Answer:

• (A) 8 cans
• (B) 9 cans (Correct answer)
• (C) 35 cans
• (D) 88 cans