Lily has 2 containers. Container A and Container B are of different capacities. If Container A is filled by a tap at a rate of 4 litres per minute and Container B is filled by a tap at a rate of 7 litres per minute, when Container A is completely filled, 8 litres of water flowed out from Container B. If Container A is filled by a tap at a rate of 6 litres per minute and Container B is filled by a tap at a rate of 2 litres per minute, when Container A is completely filled, Container B is only one-fifth-filled. What is the capacity of Container B? Express your answer in litres.

	Scenario 1		Scenario 2
Container type	Container A	Container B	Container A	Container B
Volume of the container	4 u	7 u - 8	6 p	2 p x 5 = 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 Container B
= 10 p
= 10 x 16
= 160 ℓ

Answer(s): 160 ℓ