Multiple choice

In a dairy, pipes A and B require 10 minutes and 15 minutes, respectively to fill a container of milk. Another pipe C requires 20 minutes to empty it. In how many minutes will the milk container be filled, if all the three pipes are opened together?

  1. 8.57 minutes

  2. 10.58 minutes

  3. 11.45 minutes

  4. 11.56 minutes

  5. 12.54 minutes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rate = 1/10 + 1/15 - 1/20 = (6+4-3)/60 = 7/60. Time = 60/7 = 8.57 minutes.

AI explanation

Using the Net Work formula for one minute, the combined rate is 1/10 plus 1/15 minus 1/20, which equals 6/60 plus 4/60 minus 3/60 for a total of 7/60. Taking the reciprocal gives a time of 60/7 minutes for the container to fill. Dividing 60 by 7 gives the result of 8.57 minutes.

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