Time & Work · Question 7 · Medium

A, B and C can complete a job alone in 12, 15 and 20 days respectively. How many days will they take working together?

  1. 4 days
  2. 15 days
  3. 5 days
  4. 6 days
Answer and explanation

Answer: C. 5 days

Explanation: Combined rate = 1/12 + 1/15 + 1/20 = (5 + 4 + 3)/60 = 12/60 = 1/5, so 5 days.

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