9 tanks and 8 containers can hold 68.7 litres of water.
1 tank and 1 container can hold 8 litres of water.
- How many litres of water can 1 tank hold?
- How many litres of water can 1 container hold?
- How many litres of water can 4 containers hold?
- How many litres of water can 5 containers and 9 tanks?
(a)
9 tanks + 8 containers = 68.7 --- (1)
1 tank + 1 container = 8 --- (2)
(2) x 8
1 tank + 1 container = 8
8 tanks + 8 containers = 8 x 8
8 tanks + 8 containers = 64 --- (3)
(1) - (3)
(9 tanks + 8 containers) - (8 tanks + 8 containers) = 68.7 - 64
9 tanks + 8 containers - 8 tanks - 8 containers = 4.7
9 tanks - 8 tanks + 8 containers - 8 containers = 4.7
1 tank = 4.7
Volume of 1 tank = 4.7 ℓ
(b)
Substitute 1 tank = 4.7 into (2).
1 tank + 1 container = 8
4.7 + 1 container = 8
1 container = 8 - 4.7 = 3.3
Volume of 1 container = 3.3 ℓ
(c)
Volume of 4 containers
= 4 x 3.3
= 13.2 ℓ
(d)
Volume of 5 containers and 9 tanks
= 5 x 3.3 + 9 x 4.7
= 16.5 + 42.3
= 58.8 ℓ
Answer(s): (a) 4.7 ℓ; (b) 3.3 ℓ; (c) 13.2 ℓ; (d) 58.8 ℓ