7 pails and 6 tanks can hold 36.3 litres of water.
1 pail and 1 tank can hold 5.4 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 8 tanks hold?
- How many litres of water can 4 tanks and 7 pails?
(a)
7 pails + 6 tanks = 36.3 --- (1)
1 pail + 1 tank = 5.4 --- (2)
(2) x 6
1 pail + 1 tank = 5.4
6 pails + 6 tanks = 5.4 x 6
6 pails + 6 tanks = 32.4 --- (3)
(1) - (3)
(7 pails + 6 tanks) - (6 pails + 6 tanks) = 36.3 - 32.4
7 pails + 6 tanks - 6 pails - 6 tanks = 3.9
7 pails - 6 pails + 6 tanks - 6 tanks = 3.9
1 pail = 3.9
Volume of 1 pail = 3.9 ℓ
(b)
Substitute 1 pail = 3.9 into (2).
1 pail + 1 tank = 5.4
3.9 + 1 tank = 5.4
1 tank = 5.4 - 3.9 = 1.5
Volume of 1 tank = 1.5 ℓ
(c)
Volume of 8 tanks
= 8 x 1.5
= 12 ℓ
(d)
Volume of 4 tanks and 7 pails
= 4 x 1.5 + 7 x 3.9
= 6 + 27.3
= 33.3 ℓ
Answer(s): (a) 3.9 ℓ; (b) 1.5 ℓ; (c) 12 ℓ; (d) 33.3 ℓ