Civil Services Prep

Prelims 2022 · CSAT / Quantitative Aptitude · Question 57

24 men and 12 women can do a piece of work in 30 days. In how many days can 12 men and 24 women do the same piece of work?

  1. 30 days
  2. more than 30 days
  3. Less than 30 days or more than 30 days
  4. Data is inadequate to draw any conclusion

Answer

Data is inadequate to draw any conclusion

  • Let one man's 1-day work be m and one woman's 1-day work be w. Then total work = 30(24m + 12w).
  • For 12 men + 24 women, time required = 30(24m + 12w) / (12m + 24w) = 60(m + 0.5w)/(m + 2w).
  • This depends on the unknown relation between m and w. If men and women are equally efficient, time = 30 days; if men are more efficient, time is more than 30 days; if women are more efficient, time is less than 30 days.
  • (a) Possible in one special case only, not निश्चित. Verdict: Not sufficient.
  • (b) Possible if a man is more efficient than a woman. Verdict: Not always true.
  • (c) The time may be less than or more than 30 days depending on efficiencies. Verdict: Factually possible, but the question asks for a definite conclusion.
  • (d) Since relative efficiencies are not given, no definite conclusion can be drawn. Verdict: Correct.
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