An empty tank has a capacity of 55.2 litres.Water flows from a Tap A at 3.6 litres per mimute and 2.4 litres per minute from a Tap B.Tap A was turned on first.Tap B was turned on 2 minutes later.The taps were turned off at the same time when the tank was completely filled without overflowing.How much water flowed from Tap B?
When B is turned on, A has put 3.6(2) = 7.2 litres of water into the tank. So there remain 55.2 - 7.2 = 48 litres to fill. So we have:
3.6T + 2.4T = 48 where T is the time it takes to fill the rest of the tank .......Simpifying, we have
6T = 48
T = 8 minutes
So, since B was on for 8 minutes, it put 2.4(8) -= 19.2 litres into the tank.