6 tanks and 5 pails can hold 49.7 litres of water.
1 tank and 1 pail can hold 9.1 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 7 pails and 6 tanks?
(a)
6 tanks + 5 pails = 49.7 --- (1)
1 tank + 1 pail = 9.1 --- (2)
(2) x 5
1 tank + 1 pail = 9.1
5 tanks + 5 pails = 9.1 x 5
5 tanks + 5 pails = 45.5 --- (3)
(1) - (3)
(6 tanks + 5 pails) - (5 tanks + 5 pails) = 49.7 - 45.5
6 tanks + 5 pails - 5 tanks - 5 pails = 4.2
6 tanks - 5 tanks + 5 pails - 5 pails = 4.2
1 tank = 4.2
Volume of 1 tank = 4.2 ℓ
(b)
Substitute 1 tank = 4.2 into (2).
1 tank + 1 pail = 9.1
4.2 + 1 pail = 9.1
1 pail = 9.1 - 4.2 = 4.9
Volume of 1 pail = 4.9 ℓ
(c)
Volume of 4 pails
= 4 x 4.9
= 19.6 ℓ
(d)
Volume of 7 pails and 6 tanks
= 7 x 4.9 + 6 x 4.2
= 34.3 + 25.2
= 59.5 ℓ
Answer(s): (a) 4.2 ℓ; (b) 4.9 ℓ; (c) 19.6 ℓ; (d) 59.5 ℓ