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Railways PYQCBT 1 2016

RRB NTPC · Question 74

Ravi, Rohan and Rajesh alone can complete a work in 10, 12 and 15 days respectively. In how many days can the work be completed, if all three work together? A. 4 days B. 5 days C. 3 days D. 8 days

  1. B

  2. C

  3. D

  4. A

Show answer & explanation

Answer: (D) A

Explanation

Combined daily work = 1/10 + 1/12 + 1/15 = (6 + 5 + 4)/60 = 15/60 = 1/4. Together they finish in 4 days.