8 tanks and 7 containers can hold 38.1 litres of water.
1 tank and 1 container can hold 4.9 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 8 containers hold?
- How many litres of water can 7 containers and 8 tanks?
(a)
8 tanks + 7 containers = 38.1 --- (1)
1 tank + 1 container = 4.9 --- (2)
(2) x 7
1 tank + 1 container = 4.9
7 tanks + 7 containers = 4.9 x 7
7 tanks + 7 containers = 34.3 --- (3)
(1) - (3)
(8 tanks + 7 containers) - (7 tanks + 7 containers) = 38.1 - 34.3
8 tanks + 7 containers - 7 tanks - 7 containers = 3.8
8 tanks - 7 tanks + 7 containers - 7 containers = 3.8
1 tank = 3.8
Volume of 1 tank = 3.8 ℓ
(b)
Substitute 1 tank = 3.8 into (2).
1 tank + 1 container = 4.9
3.8 + 1 container = 4.9
1 container = 4.9 - 3.8 = 1.1
Volume of 1 container = 1.1 ℓ
(c)
Volume of 8 containers
= 8 x 1.1
= 8.8 ℓ
(d)
Volume of 7 containers and 8 tanks
= 7 x 1.1 + 8 x 3.8
= 7.7 + 30.4
= 38.1 ℓ
Answer(s): (a) 3.8 ℓ; (b) 1.1 ℓ; (c) 8.8 ℓ; (d) 38.1 ℓ