Question

Two pipes can fill a water tank seperately by 12 minutes and 20 minutes a waste pipe can drain off in 30 gallons/min. If all the three pipes are open the tank fills in 30 minutes, then the capacity of water tank is

Answer 1

Answer:

hope answer will be correct

Answer 2

Answer:

The capacity of water tank is 300 gallons or 300 litres.

Explanation:

Given:

• Two pipes fill a tank 12 minutes and 20 minutes respectively.
• Third pipe can drain off in 30 minutes.

To find: The capacity of water tank

Solution:

The first pipe can fill in 12 minutes

The  second pipe can fill in 20 minutes

The third evaluation pipe can empty 30 gallons/minute

The three pipes together can fill the tank in 30 minutes

Therefore,

Work done by the first pipe  is $\frac{1}{12}$

Work done by the second pipe is $\frac{1}{20}$              

Work done by the third pipe to empty the tank = $\frac{1}{30} - (\frac{1}{12} + \frac{1}{20})$

                                                                             = $\frac{1}{30} - (\frac{12+20}{240} )$

                                                                             = $\frac{1}{30} -\frac{32}{240}$

                                                                             = $\frac{1}{30} -\frac{8}{60}$

                                                                             = $\frac{2 - 8}{60}$

                                                                             = $-\frac{6}{60}$

                                                                             = $-\frac{1}{10}$

Negative sign means emptying

Volume of $\frac{1}{10}$ part = 30 gallons

Evaluation pipe can drain in 10 minutes

In one minute third pipe  can waste 30 liters of water

Total capacity of tank = 30× 10

                                     = 300 gallons.

Hence ,Capacity of tank = 300 litres.

Final answer:

The capacity of water tank is 300 gallons or 300 litres

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