Multiple choice

The ratio of wages of A and B is 13 : 16. If A works for 9 days and B works for 12 days to complete a work, find the ratio of efficiency of A and B.

  1. 12 : 13

  2. 9 : 13

  3. 13 : 12

  4. 13 : 9

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

Efficiency is inversely proportional to time when wages are equal. Total wages paid: A = 13 × 9 = 117, B = 16 × 12 = 192. Efficiency ratio = (wage/time) = 117/9 : 192/12 = 13 : 12. Option C is correct. Option A (12:13) is the inverse ratio - a common trap.

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