Multiple choice

Mohan can do a piece of work in 25 days alone and Rohan can finish it in 20 days. They work together for 5 days & then Mohan left the work. In how many days will Rohan finish the remaining work?

  1. 20 days

  2. 9 days

  3. 14 days

  4. 11 days
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mohan's rate is 1/25, Rohan's is 1/20. Together they work at (1/25 + 1/20) = 9/100 per day. In 5 days, they complete 5 * 9/100 = 45/100 = 9/20 of the work. Remaining work is 11/20. Rohan finishes this in (11/20) / (1/20) = 11 days.

AI explanation

Taking the least common multiple of 25 and 20 as the total work, we get 100 units. Mohan works at 4 units per day and Rohan works at 5 units per day, making their combined rate 9 units per day. In 5 days of working together, they finish 45 units, leaving 55 units of work. Rohan completes the remaining 55 units at his rate of 5 units per day. The answer is 11 days.

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