Isabella has 2 containers. Container J and Container K are of different capacities. If Container J is filled by a tap at a rate of 3 litres per minute and Container K is filled by a tap at a rate of 7 litres per minute, when Container J is completely filled, 8 litres of water flowed out from Container K. If Container J is filled by a tap at a rate of 4 litres per minute and Container K is filled by a tap at a rate of 3 litres per minute, when Container J is completely filled, Container K is only half-filled. What is the capacity of Container K? Express your answer in litres.

	Scenario 1		Scenario 2
Container type	Container J	Container K	Container J	Container K
Volume of the container	3 u	7 u - 8	4 p	3 p x 2 = 6 p

Let 1 u be the time taken for Scenario 1.
Let 1 p be the time taken for Scenario 2.

3 u = 4 p --- (1)
7 u - 8 = 6 p
7 u = 6 p + 8 --- (2)

Make u the same.

(1) x 7
21 u = 28 p --- (3)

(2) x 3
21 u = 18 p + 24 --- (4)

(3) = (4)
28 p = 18 p + 24
28 p - 18 p = 24
10 p = 24
1 p = 24 ÷ 10 = 2.4

Volume of Container K
= 6 p
= 6 x 2.4
= 14.4 ℓ

Answer(s): 14.4 ℓ