Multiple choice

Two pipes can fill the cistern in 6 hr and 10 hr and third in 15hr. If all pipes are opened simultaneously, then the cistern will be filled in?

  1. 4.5

  2. 3.3

  3. 3

  4. 3.5

  5. 3.67
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Work done in 1 hour = 1/6 + 1/10 + 1/15 = (5+3+2)/30 = 10/30 = 1/3. Time taken = 3 hours.

AI explanation

Using the Net Work formula, the portion of the cistern filled in one hour is 1/6 plus 1/10 plus 1/15. Finding a common denominator of 30 gives 5/30 plus 3/30 plus 2/30, resulting in 10/30, which simplifies to 1/3. Taking the reciprocal shows the cistern will be completely filled in 3 hours.

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