A water tank can be filled by two pipes, A and B, in 4 and 6 hours, respectively. How long will it take to fill the tank if both pipes are used?
Q1. A water tank can be filled by two pipes, A and B, in 4 and 6 hours, respectively. How long will it take to fill the tank if both pipes are used?
Answer: 2.4 hours
Explanation: Rate of A = 1 / 4, rate of B = 1 / 6. Combined rate = 1 / 4 + 1 / 6 = (3 + 2) / 12 = 5 / 12. So, time = 12 / 5 = 2.4 hours.