A tank is filled in eight hours by three pipes A, B and C. Pipe A is twice as fast as pipe B, and B is twice as fast as C. How much time will pipe B alone take to fill the tank?
Q1. A tank is filled in eight hours by three pipes A, B and C. Pipe A is twice as fast as pipe B, and B is twice as fast as C. How much time will pipe B alone take to fill the tank?
Answer: 28 hours
Explanation: Let C's rate = x, then B = 2x and A = 4x; combined rate 7x fills in 8 hours so x = 1/56, and B alone (rate 2x = 1/28) takes 28 hours.