7 containers and 6 tanks can hold 69.8 litres of water.
1 container and 1 tank can hold 10.5 litres of water.
- How many litres of water can 1 container hold?
- How many litres of water can 1 tank hold?
- How many litres of water can 3 tanks hold?
- How many litres of water can 9 tanks and 7 containers?
(a)
7 containers + 6 tanks = 69.8 --- (1)
1 container + 1 tank = 10.5 --- (2)
(2) x 6
1 container + 1 tank = 10.5
6 containers + 6 tanks = 10.5 x 6
6 containers + 6 tanks = 63 --- (3)
(1) - (3)
(7 containers + 6 tanks) - (6 containers + 6 tanks) = 69.8 - 63
7 containers + 6 tanks - 6 containers - 6 tanks = 6.8
7 containers - 6 containers + 6 tanks - 6 tanks = 6.8
1 container = 6.8
Volume of 1 container = 6.8 ℓ
(b)
Substitute 1 container = 6.8 into (2).
1 container + 1 tank = 10.5
6.8 + 1 tank = 10.5
1 tank = 10.5 - 6.8 = 3.7
Volume of 1 tank = 3.7 ℓ
(c)
Volume of 3 tanks
= 3 x 3.7
= 11.1 ℓ
(d)
Volume of 9 tanks and 7 containers
= 9 x 3.7 + 7 x 6.8
= 33.3 + 47.6
= 80.9 ℓ
Answer(s): (a) 6.8 ℓ; (b) 3.7 ℓ; (c) 11.1 ℓ; (d) 80.9 ℓ