7 tanks and 6 pails can hold 59.8 litres of water.
1 tank and 1 pail can hold 8.7 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 4 pails and 7 tanks?
(a)
7 tanks + 6 pails = 59.8 --- (1)
1 tank + 1 pail = 8.7 --- (2)
(2) x 6
1 tank + 1 pail = 8.7
6 tanks + 6 pails = 8.7 x 6
6 tanks + 6 pails = 52.2 --- (3)
(1) - (3)
(7 tanks + 6 pails) - (6 tanks + 6 pails) = 59.8 - 52.2
7 tanks + 6 pails - 6 tanks - 6 pails = 7.6
7 tanks - 6 tanks + 6 pails - 6 pails = 7.6
1 tank = 7.6
Volume of 1 tank = 7.6 ℓ
(b)
Substitute 1 tank = 7.6 into (2).
1 tank + 1 pail = 8.7
7.6 + 1 pail = 8.7
1 pail = 8.7 - 7.6 = 1.1
Volume of 1 pail = 1.1 ℓ
(c)
Volume of 5 pails
= 5 x 1.1
= 5.5 ℓ
(d)
Volume of 4 pails and 7 tanks
= 4 x 1.1 + 7 x 7.6
= 4.4 + 53.2
= 57.6 ℓ
Answer(s): (a) 7.6 ℓ; (b) 1.1 ℓ; (c) 5.5 ℓ; (d) 57.6 ℓ