4 tanks and 3 pails can hold 30.9 litres of water.
1 tank and 1 pail can hold 8 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 4 pails and 4 tanks?
(a)
4 tanks + 3 pails = 30.9 --- (1)
1 tank + 1 pail = 8 --- (2)
(2) x 3
1 tank + 1 pail = 8
3 tanks + 3 pails = 8 x 3
3 tanks + 3 pails = 24 --- (3)
(1) - (3)
(4 tanks + 3 pails) - (3 tanks + 3 pails) = 30.9 - 24
4 tanks + 3 pails - 3 tanks - 3 pails = 6.9
4 tanks - 3 tanks + 3 pails - 3 pails = 6.9
1 tank = 6.9
Volume of 1 tank = 6.9 ℓ
(b)
Substitute 1 tank = 6.9 into (2).
1 tank + 1 pail = 8
6.9 + 1 pail = 8
1 pail = 8 - 6.9 = 1.1
Volume of 1 pail = 1.1 ℓ
(c)
Volume of 4 pails
= 4 x 1.1
= 4.4 ℓ
(d)
Volume of 4 pails and 4 tanks
= 4 x 1.1 + 4 x 6.9
= 4.4 + 27.6
= 32 ℓ
Answer(s): (a) 6.9 ℓ; (b) 1.1 ℓ; (c) 4.4 ℓ; (d) 32 ℓ