Question

A water tank is filled by a pipe P alone in 30 minutes and by pipe Q alone in 40
minutes. Pipe R can empty the same tank in 25 minutes. If all the three pipes are opened together, how
long will they take to fill the tank ?
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Answer 1

Answer:

She said she was going to be in the office on Monday and Friday and Friday and Friday

Answer 2

Given,

• Pipe P can alone fill the tank in 30 minutes.
• Pipe Q can Alone Fill the Tank in 40 minutes.
• Pipe R can empty the same tank in 25 minutes.

Procedure,

Let's ,

Pipe Q & R are shutdown.

Pipe P can alone fill the tank in 30 minutes. ( Given )

Pipe P can fill tank in One minute = 1/30 (1)

Let's ,

Pipe P & R are shutdown.

Pipe Q can Alone Fill the Tank in 40 minutes. ( Given )

Pipe Q can fill tank in One minute = 1/40 (2)

Let's ,

Pipe P & Q are shutdown.

Pipe R can empty the same tank in 25 minutes.(Given)

Pipe R can empty Tank in One minute = 1/25 (3)

Solution,

If All Pipes are started at same time

They Can Fill in One minute =>

$\frac{1}{30} + \frac{1}{40} - \frac{1}{25} \\ = > \frac{20 + 15 - 24}{600} \\ = > \frac{11}{600}$

So ,

They Can Fill Full Tank in 600/11 minutes.