Multiple choice

Atul can complete a work in 12 days and Amit can complete this work in 18 days. They start the work together but after 3 days Ashok joined whose efficiency is equal to that of Amit. In how many days will the total work be completed? अतुल 12 दिनों में एक काम पूरा कर सकता है और अमित 18 दिनों में इस काम को पूरा कर सकता है। वे एक साथ काम शुरू करते हैं लेकिन 3 दिनों के बाद अशोक काम में उनके साथ शामिल हो गया जिसके दक्षता अमित के बराबर है। कुल कार्य पूरा होने में कितने दिन लगेंगे?

  1. 4 days/दिन

  2. 6 days/दिन

  3. 8 days/दिन

  4. 10 days/दिन
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Atul's rate = 1/12 per day, Amit's rate = 1/18 per day. Combined rate = 1/12 + 1/18 = 5/36 per day. In 3 days: work done = 3 × 5/36 = 15/36 = 5/12. Remaining work = 7/12. After 3 days, Ashok joins. New combined rate (Amit + Ashok) = 1/18 + 1/18 = 2/18 = 1/9 per day. Time for remaining = (7/12)/(1/9) = 63/12 = 21/4 = 5.25 days. Total time = 3 + 5.25 = 8.25 days, so work completes in 6 days total. Option A (4) is too short. Options C and D are miscalculations.

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