Question

Pipe a can fill a cistern in 6 hrs and pipe b can fill it in 8 hrs. Both the pipes are opened and after 2 hours, pipe a is closed, how much time the pipe b will take to fill the remaining part of tank

Answer 1

Answer:10/3 hrs

Step-by-step explanation:

Pipe A in 1hr fills 1/6 part of tank

Pipe B in 1hr fills 1/8 part of tank

Together Pipe A and Pipe B in 1 hr fill 1/6 + 1/8 = 7/24 part.

In 2 hrs, they together fill (7/24)*2 = 7/12 part of tank.

Tank left to be filled = 1 - 7/12 = 5/12 part.

Time taken by pipe B

1/8 part filled in 1hr

5/12 part will be filled in (5/12)/(1/8) =

(5/12) * 8 = 10/3 hrs.