5 tanks and 4 pails can hold 41.2 litres of water.
1 tank and 1 pail can hold 8.5 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 9 pails hold?
- How many litres of water can 6 pails and 5 tanks?
(a)
5 tanks + 4 pails = 41.2 --- (1)
1 tank + 1 pail = 8.5 --- (2)
(2) x 4
1 tank + 1 pail = 8.5
4 tanks + 4 pails = 8.5 x 4
4 tanks + 4 pails = 34 --- (3)
(1) - (3)
(5 tanks + 4 pails) - (4 tanks + 4 pails) = 41.2 - 34
5 tanks + 4 pails - 4 tanks - 4 pails = 7.2
5 tanks - 4 tanks + 4 pails - 4 pails = 7.2
1 tank = 7.2
Volume of 1 tank = 7.2 ℓ
(b)
Substitute 1 tank = 7.2 into (2).
1 tank + 1 pail = 8.5
7.2 + 1 pail = 8.5
1 pail = 8.5 - 7.2 = 1.3
Volume of 1 pail = 1.3 ℓ
(c)
Volume of 9 pails
= 9 x 1.3
= 11.7 ℓ
(d)
Volume of 6 pails and 5 tanks
= 6 x 1.3 + 5 x 7.2
= 7.8 + 36
= 43.8 ℓ
Answer(s): (a) 7.2 ℓ; (b) 1.3 ℓ; (c) 11.7 ℓ; (d) 43.8 ℓ