Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is opened all the time and B and C are open for one hour each alternately starting with A and B, the tank will be full in:
1
1 hr
2
3 hrs
3
6 hrs
4
7 hrs
5
8 hrs
Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is opened all the time and B and C are open for one hour each alternately starting with A and B, the tank will be full in: