Multiple choice

Arun and Naimish can do a piece of work in 9 days. Arun alone can do this work in 12 days. They started the work together but after some days Arun left the work and Naimish work for last 4 days alone. Find after how many days Arun left the work ?

  1. 8 days

  2. 7 days

  3. 6 days

  4. 5 days

  5. 4 days
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Arun's rate = 1/12 per day. Combined rate = 1/9 per day. Naimish's rate = 1/9 - 1/12 = 1/36 per day. Let x be days worked together. Work done together = x/9, Naimish alone for 4 days = 4/36 = 1/9. Total work: x/9 + 1/9 = 1, so x = 8 days.

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