4 containers and 3 pails can hold 27.7 litres of water.
1 container and 1 pail can hold 7.3 litres of water.

1. How many litres of water can 1 container hold?
2. How many litres of water can 1 pail hold?
3. How many litres of water can 7 pails hold?
4. How many litres of water can 8 pails and 4 containers?

(a)
4 containers + 3 pails = 27.7 --- (1)
1 container + 1 pail = 7.3 --- (2)

(2) x 3
1 container + 1 pail = 7.3
3 containers + 3 pails = 7.3 x 3
3 containers + 3 pails = 21.9 --- (3)

(1) - (3)
(4 containers + 3 pails) - (3 containers + 3 pails) = 27.7 - 21.9
4 containers + 3 pails - 3 containers - 3 pails = 5.8
4 containers - 3 containers + 3 pails - 3 pails = 5.8

1 container = 5.8

Volume of 1 container = 5.8 ℓ

(b)
Substitute 1 container = 5.8 into (2).
1 container + 1 pail = 7.3
5.8 + 1 pail = 7.3

1 pail = 7.3 - 5.8 = 1.5

Volume of 1 pail = 1.5 ℓ

(c)
Volume of 7 pails
= 7 x 1.5
= 10.5 ℓ

(d)
Volume of 8 pails and 4 containers
= 8 x 1.5 + 4 x 5.8
= 12 + 23.2
= 35.2 ℓ

Answer(s): (a) 5.8 ℓ; (b) 1.5 ℓ; (c) 10.5 ℓ; (d) 35.2 ℓ