Mrs. Vijaya takes a total of 9 hours 50 minutes in walking a distance and running back to same place where she started. She could walk both ways in 12 hrs 20 minutes. The time taken by her to run both ways is:

• A. 7 hours 45 min
• B. 7 hours 35 min
• C. 7 hours 15 min
• D. 7 hours 20 min