5 tanks and 4 pails can hold 23.7 litres of water.
1 tank and 1 pail can hold 5 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 5 pails hold?
- How many litres of water can 7 pails and 5 tanks?
(a)
5 tanks + 4 pails = 23.7 --- (1)
1 tank + 1 pail = 5 --- (2)
(2) x 4
1 tank + 1 pail = 5
4 tanks + 4 pails = 5 x 4
4 tanks + 4 pails = 20 --- (3)
(1) - (3)
(5 tanks + 4 pails) - (4 tanks + 4 pails) = 23.7 - 20
5 tanks + 4 pails - 4 tanks - 4 pails = 3.7
5 tanks - 4 tanks + 4 pails - 4 pails = 3.7
1 tank = 3.7
Volume of 1 tank = 3.7 ℓ
(b)
Substitute 1 tank = 3.7 into (2).
1 tank + 1 pail = 5
3.7 + 1 pail = 5
1 pail = 5 - 3.7 = 1.3
Volume of 1 pail = 1.3 ℓ
(c)
Volume of 5 pails
= 5 x 1.3
= 6.5 ℓ
(d)
Volume of 7 pails and 5 tanks
= 7 x 1.3 + 5 x 3.7
= 9.1 + 18.5
= 27.6 ℓ
Answer(s): (a) 3.7 ℓ; (b) 1.3 ℓ; (c) 6.5 ℓ; (d) 27.6 ℓ