Question

Pipe A can fill swimming pool in 8 hours ; pipe B can fill the swimming pool in 10 hours while pipe C can fill the swimming pool in 12 hours. All the pipes are started at 9:am. while pipe A is closed at 11:am. and the remaining two pipes complete work . Approximately at what time will the work be finished ?

Answer 1

pipe B can fill 7hour

Answer 2

Find Pipe A Rate:

Rate = 1/8

.

Find Pipe B Rate:

Rate = 1/10

.

Find Pipe C Rate:

Rate = 1/12

.

Find number of hours between 9 am to 111 am:

9 am to 11 am = 2 hours.

.

Find amount of water filled in the 2 hours:

Pipe A + Pipe B + Pipe C:

1 hour = 1/8 + 1/10 + 1/12 = 37/120

2 hour = 37/120 x 2 = 37/60

.

Amount of water that is needed to fill:

1 - 37/60 = 23/60

.

Find Time need for Pipe B and Pipe C to fill:

Pipe B + Pipe C :

1 hour = 1/10 + 1/12 = 11/60

Number of hours needed = 23/60 ÷ 11/60 = 2 1/11 hours

.

Find completion time:

2 1/11 = 2 hours (approx)

11 am + 2 h = 1 pm

.

Answer: The job will be completed at 1 pm