Multiple choice

A is 40% more efficient than B. C does half of the work done by A and B together. If C alone does the work in 36 days, then A, B and C together can do the work in ?

  1. 10 days

  2. 12 days

  3. 8 days

  4. 6 days

  5. 16 days
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If A is 40% more efficient than B, then A:B efficiency ratio = 140:100 = 7:5. C does half the combined work of A and B, so C's efficiency = (7+5)/2 = 6 units. If C alone takes 36 days (C's total work = 6×36 = 216), then combined (A+B+C) efficiency = 7+5+6 = 18. Time = 216/18 = 12 days.

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