A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?
Q1. A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?
Answer: 3 hrs 45 min
Explanation: One tap fills half the tank in 3 hours; four taps fill the remaining half at rate 4×(1/6) = 2/3 per hour, taking 45 minutes; total time = 3 h 45 min.