Task: Question Answering
Input (English): Question: A can do a piece of work in 7 days and B can do it in 6 days how long will they both work together to complete the work?

 Option A: 6/11

 Option B: 8/13

 Option C: 3/13

 Option D: 9/11

 Option E: 10/13
Output (English): Option C