Subject: mathqa
Question: jerry travels 8 miles at an average speed of 40 miles per hour , stops for 13 minutes , and then travels another 20 miles at an average speed of 60 miles per hour . what is jerry ’ s average speed , in miles per hour , for this trip ?
Option: 
A: 48
B: 42.5
C: 52.5
D: 44
Answer: A