## Pipes and Cistern

#### Pipes and Cistern

1. A cistern is normally filled in 8 hrs. but takes 2 hrs. longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty it in ?

1. Here x = 8 hrs. and y = 8 + 2 = 10 hrs.
Now, applying the given rule, we have the
Required answer = (8 x 10) /(10 - 8) = 40 hrs.

##### Correct Option: B

Here x = 8 hrs. and y = 8 + 2 = 10 hrs.
Now, applying the given rule, we have the
Required answer = (8 x 10) /(10 - 8) = 40 hrs.

1. A pipe can empty a tank in 12 minutes and another pipe can empty it in 16 minutes. If both the pipes are opened simultaneously, find the time in which a full tank is emptied ?

1. Required answer = (12 x 16) /(12 + 16) = 48 / 7 = 66/7 minutes.

##### Correct Option: D

Required answer = (12 x 16) /(12 + 16) = 48 / 7 = 66/7 minutes.

1. A cistern is normally filled in 8 hours but takes two hours longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty it in ?

1. Work done by leak in 1 hour = (1/8 - 1/10) = 1/40

##### Correct Option: D

Work done by leak in 1 hour = (1/8 - 1/10) = 1/40
∴ The leak will empty the cistern in 40 hours.

1. If a pipe fills a tank in 6 h, then what part of the tank will the pipe fill in 1 h?

1. We know that, when a pipe fills a tank in m h, then the part of tank filled in 1 h = 1/m

##### Correct Option: B

We know that, when a pipe fills a tank in m h, then the part of tank filled in 1 h = 1/m
Here, m = 6
∴ Required part of the tank to be filled in 1h = 1/6 part