6 tanks and 5 pails can hold 43.1 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 6 pails hold?
- How many litres of water can 7 pails and 6 tanks?
(a)
6 tanks + 5 pails = 43.1 --- (1)
1 tank + 1 pail = 8 --- (2)
(2) x 5
1 tank + 1 pail = 8
5 tanks + 5 pails = 8 x 5
5 tanks + 5 pails = 40 --- (3)
(1) - (3)
(6 tanks + 5 pails) - (5 tanks + 5 pails) = 43.1 - 40
6 tanks + 5 pails - 5 tanks - 5 pails = 3.1
6 tanks - 5 tanks + 5 pails - 5 pails = 3.1
1 tank = 3.1
Volume of 1 tank = 3.1 ℓ
(b)
Substitute 1 tank = 3.1 into (2).
1 tank + 1 pail = 8
3.1 + 1 pail = 8
1 pail = 8 - 3.1 = 4.9
Volume of 1 pail = 4.9 ℓ
(c)
Volume of 6 pails
= 6 x 4.9
= 29.4 ℓ
(d)
Volume of 7 pails and 6 tanks
= 7 x 4.9 + 6 x 3.1
= 34.3 + 18.6
= 52.9 ℓ
Answer(s): (a) 3.1 ℓ; (b) 4.9 ℓ; (c) 29.4 ℓ; (d) 52.9 ℓ