A tank can be filled by one pump in 50 minutes and by another pump in 60 minutes. A third pump can drain the tank in 75 minutes. If all 3 pumps go into operation, how long will it take to fill the tank?

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Answer:

42 6/7 minutes

Step-by-step explanation:

Each minute, the first pump adds 1/50 of a tank; the second pump adds 1/60 of a tank; and the third pump subtracts 1/75 of a tank. Then, each minute the total amount added is ...

... (1/50) + (1/60) - (1/75) = 6/300 + 5/300 - 4/300

... = 7/300 . . . . of a tank.

Then in 300/7 minutes, or 42 6/7 minutes, the tank will be full.

Using the together rate, it is found that the 3 pumps together would fill the tank in 42.86 minutes.

What is the together rate?

The together rate is given by the sum of each separate rate.

In this problem, the rates are given by: 1/50, 1/60 and -1/75.

Hence, the together rate is given by:

[tex]\frac{1}{x} = \frac{1}{50} + \frac{1}{60} - \frac{1}{75}[/tex]

Applying the least common multiple:

[tex]\frac{1}{x} = \frac{6 + 5 - 4}{300}[/tex]

[tex]7x = 300[/tex]

[tex]x = \frac{300}{7}[/tex]

[tex]x = 42.86[/tex]

Hence, it is found that the 3 pumps together would fill the tank in 42.86 minutes.

More can be learned about the together rate at https://brainly.com/question/25159431