William has 2 tanks. Tank L and Tank M are of different capacities. If Tank L is filled by a tap at a rate of 4 litres per minute and Tank M is filled by a tap at a rate of 7 litres per minute, when Tank L is completely filled, 8 litres of water flowed out from Tank M. If Tank L is filled by a tap at a rate of 6 litres per minute and Tank M is filled by a tap at a rate of 5 litres per minute, when Tank L is completely filled, Tank M is only half-filled. What is the capacity of Tank M? Express your answer in litres.
|
Scenario 1 |
Scenario 2 |
Tank type |
Tank L |
Tank M |
Tank L |
Tank M |
Volume of the tank |
4 u |
7 u - 8 |
6 p |
5 p x 2 = 10 p |
Let 1 u be the time taken for Scenario 1.
Let 1 p be the time taken for Scenario 2.
4 u = 6 p --- (1)
7 u - 8 = 10 p
7 u = 10 p + 8 --- (2)
Make u the same.
(1) x 7
28 u = 42 p --- (3)
(2) x 4
28 u = 40 p + 32 --- (4)
(3) = (4)
42 p = 40 p + 32
42 p - 40 p = 32
2 p = 32
1 p = 32 ÷ 2 = 16
Volume of Tank M
= 10 p
= 10 x 16
= 160 ℓ
Answer(s): 160 ℓ