Level 3
Beryl has 2 containers. A and B of different capacities. If Container A is filled by a tap at a rate of 3 litres per minute and Container B is filled by a tap at a rate of 5 litres per minute, when Container A is completely filled, 5 litres of water flowed out from Container B. 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 3 litres per minute, when Container A is completely filled, Container B is only half-filled. What is the capacity of Container B?