7 tanks and 6 pails can hold 68.7 litres of water.
1 tank and 1 pail can hold 10.3 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 3 pails and 7 tanks?
(a)
7 tanks + 6 pails = 68.7 --- (1)
1 tank + 1 pail = 10.3 --- (2)
(2) x 6
1 tank + 1 pail = 10.3
6 tanks + 6 pails = 10.3 x 6
6 tanks + 6 pails = 61.8 --- (3)
(1) - (3)
(7 tanks + 6 pails) - (6 tanks + 6 pails) = 68.7 - 61.8
7 tanks + 6 pails - 6 tanks - 6 pails = 6.9
7 tanks - 6 tanks + 6 pails - 6 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 = 10.3
6.9 + 1 pail = 10.3
1 pail = 10.3 - 6.9 = 3.4
Volume of 1 pail = 3.4 ℓ
(c)
Volume of 5 pails
= 5 x 3.4
= 17 ℓ
(d)
Volume of 3 pails and 7 tanks
= 3 x 3.4 + 7 x 6.9
= 10.2 + 48.3
= 58.5 ℓ
Answer(s): (a) 6.9 ℓ; (b) 3.4 ℓ; (c) 17 ℓ; (d) 58.5 ℓ