3 tanks and 2 pails can hold 25.1 litres of water.
1 tank and 1 pail can hold 9 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 5 pails and 3 tanks?
(a)
3 tanks + 2 pails = 25.1 --- (1)
1 tank + 1 pail = 9 --- (2)
(2) x 2
1 tank + 1 pail = 9
2 tanks + 2 pails = 9 x 2
2 tanks + 2 pails = 18 --- (3)
(1) - (3)
(3 tanks + 2 pails) - (2 tanks + 2 pails) = 25.1 - 18
3 tanks + 2 pails - 2 tanks - 2 pails = 7.1
3 tanks - 2 tanks + 2 pails - 2 pails = 7.1
1 tank = 7.1
Volume of 1 tank = 7.1 ℓ
(b)
Substitute 1 tank = 7.1 into (2).
1 tank + 1 pail = 9
7.1 + 1 pail = 9
1 pail = 9 - 7.1 = 1.9
Volume of 1 pail = 1.9 ℓ
(c)
Volume of 9 pails
= 9 x 1.9
= 17.1 ℓ
(d)
Volume of 5 pails and 3 tanks
= 5 x 1.9 + 3 x 7.1
= 9.5 + 21.3
= 30.8 ℓ
Answer(s): (a) 7.1 ℓ; (b) 1.9 ℓ; (c) 17.1 ℓ; (d) 30.8 ℓ