Ajit and Bimal can do a piece of work in 5, and 8 days, respectively, while Chandan can destroy the same work in 12 days. Ajit works on the 1st day, Bimal works on the 2nd day, Chandan works on the 3rd day and so on. They follow the same pattern until the work gets completed. How many days will it take for the work to be completed the first time?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 10.
Work done per day Ajit = 1/5 and Bimal = 1/8 and Chandan = −1/12
In 3 days total work = 1/5 + 1/8 − 1/12 = (24 + 15 − 10) / 120 = 29 / 120
After 3 days → 29/120 of work done
Cycle repeats: After 6 days → 58/120 and After 9 days → 87/120
Next day (10th) Ajit works → adds 1/5 = 24/120
Total after 10 days = 87 + 24 = 111/120
Remaining = 9/120
Next day (11th) Bimal works → rate = 1/8 = 15/120
He’ll complete remaining in (9/120) ÷ (15/120) = 9/15 day
So total time = 10 + 9/15 = 10day