WBCS.LIVE practice question

A swimming pool can be filled by 2 pipes together in 6 hours. If the longer pipe alone takes 5 hours less than the smaller to fill the pool, the time in which the longer pipe alone would fill the pool is

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 9 hours
  2. 10 hours
  3. 6 hours
  4. 8.5 hours

Correct answer and explanation

Correct answer: 10 hours

Explanation: āœ… Correct Answer: B. 10 hours šŸ“š Explanation: To solve this, let the time taken by the longer pipe be x hours. Then the smaller pipe takes x + 5 hours. Their combined work rate is 1/x + 1/(x + 5) = 1/6. Solving the equation (x + 5 + x) / (x * (x + 5)) = 1/6 leads to x = 10. Therefore, the longer pipe alone can fill the entire swimming pool in exactly 10 hours.