Question

Four pipelines A, B, C, and D can fill a tank separately in 8 hrs, 16 hrs, 12 hrs, and 16 hrs, respectively. If all the four pipes are opened, how long will it take to
fill half of the tank?​

Answer 1

Answer:

1.5 hours

Step-by-step explanation:

Time taken by each pipe to fill tank separately:

A = 8

B = 16

C = 12

D = 16

work done in 1 hr :

by A = 1/8

by B = 1/16

by C = 1/12

by D = 1/16

work done in 1 hr when all pipes are opened :

1/8 + 1/16 + 1/12 + 1/16

= 1/3

time taken for tank to be full when all pipes are open:

3 hrs

time taken to fill half of the tank : 3/2 = 1.5 hrs