Multiple choice

Directions: The following question is accompanied by statements A, B and C. You have to determine the statement(s) which is/are sufficient to answer the question. What is the amount of work done by A, B, C and D in an hour? A. A, who can complete 50% of the total work in 10 hours, is 30% more efficient than B. B. B is 50% more efficient than C and 20% more efficient than D. C.The ratio of efficiency of B, C and D is 5 : 7 : 8.

  1. Only C alone is sufficient

  2. Only A and B together are sufficient

  3. Only A and C together are sufficient

  4. Only A and either B or C together are sufficient

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

Statement A gives A's efficiency relative to B. Statement B gives B's efficiency relative to C and D. Statement C gives the ratio of B, C, and D. To find the total work done by A, B, C, and D in an hour, we need the absolute work rate of at least one person, which is provided by A. Combining A with either B or C allows us to determine the rates of all four.

AI explanation

Statement A gives the work rate of A as 0.5 divided by 10, or 1/20 of the work per hour, and states A is 30% more efficient than B, which allows you to calculate B's rate as 1/26 of the work per hour. Statement B provides the relative efficiencies of B, C, and D, and statement C provides an alternative ratio for the efficiencies of B, C, and D. Since statement B and statement C give the same comparative ratios for B to C and B to D, pairing either statement B or statement C with statement A allows you to calculate the hourly rates of C and D, which means only A and either B or C together are sufficient.

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