Answer: Sally will catch up with Jane after 50 minutes.
Explanation:
Since we have given that
Speed of Jane of biking = 12 mph
After 10 minutes,
Speed of Sally of biking = 15 mph
Let the distance be 'x'.
According to question, our required equation becomes,

Thus, total distance would be 10 miles.
So, the time taken by Sally to catch up with Jane is given by

Hence, Sally will catch up with Jane after 50 minutes.