Three pipes are attached to a tank. One of them can fill the tank alone in 40 minutes. The other two when opened together, can fill the tank to half in 12 minutes. In how much the tank can be filled to quarter of its capacity if all the pipes are opened?
1
3 minutes
2
3 minutes and 15 seconds
3
3 minutes and 30 seconds
4
3 minutes and 45 seconds
5
4 minutes