6 pails and 5 tanks can hold 40.4 litres of water.
1 pail and 1 tank can hold 7.2 litres of water.
- How many litres of water can 1 pail hold?
- How many litres of water can 1 tank hold?
- How many litres of water can 7 tanks hold?
- How many litres of water can 7 tanks and 6 pails?
(a)
6 pails + 5 tanks = 40.4 --- (1)
1 pail + 1 tank = 7.2 --- (2)
(2) x 5
1 pail + 1 tank = 7.2
5 pails + 5 tanks = 7.2 x 5
5 pails + 5 tanks = 36 --- (3)
(1) - (3)
(6 pails + 5 tanks) - (5 pails + 5 tanks) = 40.4 - 36
6 pails + 5 tanks - 5 pails - 5 tanks = 4.4
6 pails - 5 pails + 5 tanks - 5 tanks = 4.4
1 pail = 4.4
Volume of 1 pail = 4.4 ℓ
(b)
Substitute 1 pail = 4.4 into (2).
1 pail + 1 tank = 7.2
4.4 + 1 tank = 7.2
1 tank = 7.2 - 4.4 = 2.8
Volume of 1 tank = 2.8 ℓ
(c)
Volume of 7 tanks
= 7 x 2.8
= 19.6 ℓ
(d)
Volume of 7 tanks and 6 pails
= 7 x 2.8 + 6 x 4.4
= 19.6 + 26.4
= 46 ℓ
Answer(s): (a) 4.4 ℓ; (b) 2.8 ℓ; (c) 19.6 ℓ; (d) 46 ℓ