Question

There are two pipes in a tank if pipe A is opened the tank will be filled in 20 minutes ,and if pipe B is opened it will be filled in 25 minutes.If both are open together in how many minutes will it be filled ?

• A. 10 minutes
• B. 22.5 minutes
• C. 11⅟₉ minutes
• D. 45 minutes

Answer 1

Answer:

C. 11⅟₉ minutes

Total capacity of tank = LCM[20, 25] = 100 Efficiency of A = 100/20 = 5 Efficiency of B = 100/25 = 4 Efficiency of A + B = 5 + 4 = 9 Time taken by both pipes together = 100/9 = 11⅟₉ minutes