6 containers and 5 tanks can hold 57.3 litres of water.
1 container and 1 tank can hold 10 litres of water.

1. How many litres of water can 1 container hold?
2. How many litres of water can 1 tank hold?
3. How many litres of water can 6 tanks hold?
4. How many litres of water can 8 tanks and 6 containers?

(a)
6 containers + 5 tanks = 57.3 --- (1)
1 container + 1 tank = 10 --- (2)

(2) x 5
1 container + 1 tank = 10
5 containers + 5 tanks = 10 x 5
5 containers + 5 tanks = 50 --- (3)

(1) - (3)
(6 containers + 5 tanks) - (5 containers + 5 tanks) = 57.3 - 50
6 containers + 5 tanks - 5 containers - 5 tanks = 7.3
6 containers - 5 containers + 5 tanks - 5 tanks = 7.3

1 container = 7.3

Volume of 1 container = 7.3 ℓ

(b)
Substitute 1 container = 7.3 into (2).
1 container + 1 tank = 10
7.3 + 1 tank = 10

1 tank = 10 - 7.3 = 2.7

Volume of 1 tank = 2.7 ℓ

(c)
Volume of 6 tanks
= 6 x 2.7
= 16.2 ℓ

(d)
Volume of 8 tanks and 6 containers
= 8 x 2.7 + 6 x 7.3
= 21.6 + 43.8
= 65.4 ℓ

Answer(s): (a) 7.3 ℓ; (b) 2.7 ℓ; (c) 16.2 ℓ; (d) 65.4 ℓ