9 pails and 8 tanks can hold 63.9 litres of water.
1 pail and 1 tank can hold 7.3 litres of water.
- How many litres of water can 1 pail hold?
- How many litres of water can 1 tank hold?
- How many litres of water can 4 tanks hold?
- How many litres of water can 8 tanks and 9 pails?
(a)
9 pails + 8 tanks = 63.9 --- (1)
1 pail + 1 tank = 7.3 --- (2)
(2) x 8
1 pail + 1 tank = 7.3
8 pails + 8 tanks = 7.3 x 8
8 pails + 8 tanks = 58.4 --- (3)
(1) - (3)
(9 pails + 8 tanks) - (8 pails + 8 tanks) = 63.9 - 58.4
9 pails + 8 tanks - 8 pails - 8 tanks = 5.5
9 pails - 8 pails + 8 tanks - 8 tanks = 5.5
1 pail = 5.5
Volume of 1 pail = 5.5 ℓ
(b)
Substitute 1 pail = 5.5 into (2).
1 pail + 1 tank = 7.3
5.5 + 1 tank = 7.3
1 tank = 7.3 - 5.5 = 1.8
Volume of 1 tank = 1.8 ℓ
(c)
Volume of 4 tanks
= 4 x 1.8
= 7.2 ℓ
(d)
Volume of 8 tanks and 9 pails
= 8 x 1.8 + 9 x 5.5
= 14.4 + 49.5
= 63.9 ℓ
Answer(s): (a) 5.5 ℓ; (b) 1.8 ℓ; (c) 7.2 ℓ; (d) 63.9 ℓ