Question

a cistern can be filled by one tap in four hours and another tap in 3 hours. How long will it take to fill the cistern if both tap are open together?
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Answer 1

Answer:

Time taken by the first tap to fill the cistern =4 hours.

Time taken by the second tap to fill the cistern =3 hours

Work done by the first tap in 1 hour = ¹/4

Work done by the second tap in 1 hour = ¹/3

Step-by-step explanation:

Hope this answer will be helpful..

Answer 2

Answer:

12/7  Hours

Step-by-step explanation:     Tap A fills cistern in 4 hours

In 1 Hour tap A can fill = 1/4 part.

In 1 Hour tap B can fill = 1/3 part .

If both taps are open then, In 1 Hour tap A and B can fill = 1/4 + 1/3.

                                                                                               = (3+4) /12 =7/12 part

Therefore  A & B can fill cistern in 12/7 Hours.