Multiple choice

To do a piece of work B would take 3 times as long as A & C together and C twice as long as A & B together. The three men working together can complete the work in 12 days. How long B alone would take to do it alone?

  1. 36

  2. 30

  3. 45

  4. 48

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

Given 1/A + 1/B + 1/C = 1/12. Also B = 3(A+C) and C = 2(A+B). Let total work = 1 unit. A+B+C = 1/12. Substituting the relationships and solving gives B = 1/48, so B alone takes 48 days. This requires solving a system of equations for work rates.

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