Multiple choice

Directions: The following question is accompanied by three statements A, B and C. You have to determine which statement(s) is/are necessary/sufficient to answer the question. In how many days will the work be completed by Rohit and Pankaj when they work together? A. Rohit is 50% more efficient than Pankaj, and Pankaj is 50% less efficient than Rahul. B. Rahul and Rohit together can complete the work in 20 days. C. If the efficiency of Pankaj becomes 4 times, he can complete the work in 17.5 days.

  1. Only A and B

  2. Only A and C

  3. Only A and either B or C

  4. Only B and either A or C

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement A gives efficiency ratios. Statement B allows calculating the work rate of Rohit and Pankaj using Rahul's rate. Statement C allows calculating Pankaj's rate directly. Thus, A and B or A and C are sufficient.

AI explanation

To find the time taken by Rohit and Pankaj, their individual work rates must be determined. Statement A provides relative efficiencies by linking Rohit, Pankaj, and Rahul to one another. Statement B gives the combined work rate of Rahul and Rohit, and statement C gives the time Pankaj takes if his efficiency changes, allowing his original rate to be calculated. Statement A must be paired with either B or C to establish the absolute work rates for everyone and calculate the required time.

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