Task: Question Answering
Input (English): Question: Ravi can do a piece of work in 30 days while Prakash can do it in 40 days. In how many days will they finish it together?

 Option A: 17 1/7 days

 Option B: 5 days

 Option C: 6 days

 Option D: 9 days

 Option E: 10 days
Output (English): Option A