5 pails and 4 containers can hold 47.1 litres of water.
1 pail and 1 container can hold 9.9 litres of water.

1. How many litres of water can 1 pail hold?
2. How many litres of water can 1 container hold?
3. How many litres of water can 3 containers hold?
4. How many litres of water can 8 containers and 5 pails?

(a)
5 pails + 4 containers = 47.1 --- (1)
1 pail + 1 container = 9.9 --- (2)

(2) x 4
1 pail + 1 container = 9.9
4 pails + 4 containers = 9.9 x 4
4 pails + 4 containers = 39.6 --- (3)

(1) - (3)
(5 pails + 4 containers) - (4 pails + 4 containers) = 47.1 - 39.6
5 pails + 4 containers - 4 pails - 4 containers = 7.5
5 pails - 4 pails + 4 containers - 4 containers = 7.5

1 pail = 7.5

Volume of 1 pail = 7.5 ℓ

(b)
Substitute 1 pail = 7.5 into (2).
1 pail + 1 container = 9.9
7.5 + 1 container = 9.9

1 container = 9.9 - 7.5 = 2.4

Volume of 1 container = 2.4 ℓ

(c)
Volume of 3 containers
= 3 x 2.4
= 7.2 ℓ

(d)
Volume of 8 containers and 5 pails
= 8 x 2.4 + 5 x 7.5
= 19.2 + 37.5
= 56.7 ℓ

Answer(s): (a) 7.5 ℓ; (b) 2.4 ℓ; (c) 7.2 ℓ; (d) 56.7 ℓ