3 tanks and 2 pails can hold 20.7 litres of water.
1 tank and 1 pail can hold 8.3 litres of water.
- How many litres of water can 1 tank hold?
- How many litres of water can 1 pail hold?
- How many litres of water can 4 pails hold?
- How many litres of water can 8 pails and 3 tanks?
(a)
3 tanks + 2 pails = 20.7 --- (1)
1 tank + 1 pail = 8.3 --- (2)
(2) x 2
1 tank + 1 pail = 8.3
2 tanks + 2 pails = 8.3 x 2
2 tanks + 2 pails = 16.6 --- (3)
(1) - (3)
(3 tanks + 2 pails) - (2 tanks + 2 pails) = 20.7 - 16.6
3 tanks + 2 pails - 2 tanks - 2 pails = 4.1
3 tanks - 2 tanks + 2 pails - 2 pails = 4.1
1 tank = 4.1
Volume of 1 tank = 4.1 ℓ
(b)
Substitute 1 tank = 4.1 into (2).
1 tank + 1 pail = 8.3
4.1 + 1 pail = 8.3
1 pail = 8.3 - 4.1 = 4.2
Volume of 1 pail = 4.2 ℓ
(c)
Volume of 4 pails
= 4 x 4.2
= 16.8 ℓ
(d)
Volume of 8 pails and 3 tanks
= 8 x 4.2 + 3 x 4.1
= 33.6 + 12.3
= 45.9 ℓ
Answer(s): (a) 4.1 ℓ; (b) 4.2 ℓ; (c) 16.8 ℓ; (d) 45.9 ℓ