7 pails and 6 containers can hold 68.3 litres of water.
1 pail and 1 container can hold 10 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 9 containers hold?
4. How many litres of water can 3 containers and 7 pails?

(a)
7 pails + 6 containers = 68.3 --- (1)
1 pail + 1 container = 10 --- (2)

(2) x 6
1 pail + 1 container = 10
6 pails + 6 containers = 10 x 6
6 pails + 6 containers = 60 --- (3)

(1) - (3)
(7 pails + 6 containers) - (6 pails + 6 containers) = 68.3 - 60
7 pails + 6 containers - 6 pails - 6 containers = 8.3
7 pails - 6 pails + 6 containers - 6 containers = 8.3

1 pail = 8.3

Volume of 1 pail = 8.3 ℓ

(b)
Substitute 1 pail = 8.3 into (2).
1 pail + 1 container = 10
8.3 + 1 container = 10

1 container = 10 - 8.3 = 1.7

Volume of 1 container = 1.7 ℓ

(c)
Volume of 9 containers
= 9 x 1.7
= 15.3 ℓ

(d)
Volume of 3 containers and 7 pails
= 3 x 1.7 + 7 x 8.3
= 5.1 + 58.1
= 63.2 ℓ

Answer(s): (a) 8.3 ℓ; (b) 1.7 ℓ; (c) 15.3 ℓ; (d) 63.2 ℓ