A 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 together?
Q1. A 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 together?
Answer: 2.4 hours
Explanation: Rate of A = 1 / 4, Rate of B = 1 / 6. Combined rate = 1 / 4 + 1 / 6 = 5 / 12. Time = 1 / (5 / 12) = 12 / 5 = 2.4 hours.