Multiple choice

A can complete a piece of work in 20 days and B can complete 20% of the work in 6 days. If they work together in how many days can they finish 50% of the work?

  1. 6

  2. 8

  3. 9

  4. 12
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A's work rate: 1/20 work per day. B completes 20% in 6 days, so B's rate = 0.2/6 = 1/30 work per day. Combined rate: 1/20 + 1/30 = 5/60 = 1/12 work per day. For 50% of work: (1/2) ÷ (1/12) = 6 days. Together they complete half the work in exactly 6 days.

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