Question 46
Three taps A, B, and C can fill a tank in 10, 15, and 30 hours respectively. If all three taps are opened together, in how many hours will the tank be filled?
Combined rate = 1/10 + 1/15 + 1/30 = (3 + 2 + 1)/30 = 6/30 = 1/5 tank per hour. Time = 5 hours.