8 pails and 7 tanks can hold 67.1 litres of water.
1 pail and 1 tank can hold 8.6 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 6 tanks hold?
- How many litres of water can 8 tanks and 8 pails?
(a)
8 pails + 7 tanks = 67.1 --- (1)
1 pail + 1 tank = 8.6 --- (2)
(2) x 7
1 pail + 1 tank = 8.6
7 pails + 7 tanks = 8.6 x 7
7 pails + 7 tanks = 60.2 --- (3)
(1) - (3)
(8 pails + 7 tanks) - (7 pails + 7 tanks) = 67.1 - 60.2
8 pails + 7 tanks - 7 pails - 7 tanks = 6.9
8 pails - 7 pails + 7 tanks - 7 tanks = 6.9
1 pail = 6.9
Volume of 1 pail = 6.9 ℓ
(b)
Substitute 1 pail = 6.9 into (2).
1 pail + 1 tank = 8.6
6.9 + 1 tank = 8.6
1 tank = 8.6 - 6.9 = 1.7
Volume of 1 tank = 1.7 ℓ
(c)
Volume of 6 tanks
= 6 x 1.7
= 10.2 ℓ
(d)
Volume of 8 tanks and 8 pails
= 8 x 1.7 + 8 x 6.9
= 13.6 + 55.2
= 68.8 ℓ
Answer(s): (a) 6.9 ℓ; (b) 1.7 ℓ; (c) 10.2 ℓ; (d) 68.8 ℓ