9 pails and 8 containers can hold 56.8 litres of water.
1 pail and 1 container can hold 6.5 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 9 containers and 9 pails?

(a)
9 pails + 8 containers = 56.8 --- (1)
1 pail + 1 container = 6.5 --- (2)

(2) x 8
1 pail + 1 container = 6.5
8 pails + 8 containers = 6.5 x 8
8 pails + 8 containers = 52 --- (3)

(1) - (3)
(9 pails + 8 containers) - (8 pails + 8 containers) = 56.8 - 52
9 pails + 8 containers - 8 pails - 8 containers = 4.8
9 pails - 8 pails + 8 containers - 8 containers = 4.8

1 pail = 4.8

Volume of 1 pail = 4.8 ℓ

(b)
Substitute 1 pail = 4.8 into (2).
1 pail + 1 container = 6.5
4.8 + 1 container = 6.5

1 container = 6.5 - 4.8 = 1.7

Volume of 1 container = 1.7 ℓ

(c)
Volume of 3 containers
= 3 x 1.7
= 5.1 ℓ

(d)
Volume of 9 containers and 9 pails
= 9 x 1.7 + 9 x 4.8
= 15.3 + 43.2
= 58.5 ℓ

Answer(s): (a) 4.8 ℓ; (b) 1.7 ℓ; (c) 5.1 ℓ; (d) 58.5 ℓ