RRB NTPC · Question 9

Three pipes, A and B and C, can fill a tank in 15 hours, 12 hours, and 18 hours, respectively. If both pipes A and C are opened simultaneously into the empty tank, then the time taken (in hours) to fill the tank will be:

1. A

   \(8\frac{2}{{11}}\)

2. B

   \(6\frac{5}{9}\)

3. C

   \(7\frac{2}{3}\)

4. D

   \(9\frac{3}{5}\)