It takes Michelle 20 minutes to jog around the race course one time, and 25 minutes to jog around a second time. What is her average speed in miles per hour for the whole jog if the course is 3 miles long?
A. 4
B. 6
C. 8
D. 10
E. 12
Average speed = total distance / total time
Total distance covered = 6 miles; total time = 45 minutes = 0.75 hours
Average speed = 6/ 0.75 = 8 miles/hour