Multiple choice

When working alone A, B and C can complete a piece of work in 8, 12 and 30 days respectively. At the most only two people can work on each day and nobody works for more than two consecutive days. What is the minimum number of days that they will take to finish the work?

  1. 5 4/25

  2. 6 4/21

  3. 6 4/25

  4. 7 4/25
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The total work is 120 units (LCM of 8, 12, 30). A, B, and C do 15, 10, and 4 units per day respectively. To minimize days, we maximize work per day using the two most efficient workers (A and B) for two days, then rotate to keep the constraint of no more than two consecutive days for anyone.

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