Greg is training for a marathon by running to and from work

[swerve]

Greg is training for a marathon by running to and from work each day, a distance of 12 miles each way. He runs from home to work at an average speed of 6 miles per hour and returns at an average speed of 4 miles per hour. What is Greg's average speed, in miles per hour, for the round trip?

A. 5.5
B. 5.0
C. 4.8
D. 2.5
E. 2.4

The OA is C

Source: Princeton Review

[Scott@TargetTestPrep]

Greg is training for a marathon by running to and from work each day, a distance of 12 miles each way. He runs from home to work at an average speed of 6 miles per hour and returns at an average speed of 4 miles per hour. What is Greg's average speed, in miles per hour, for the round trip?

A. 5.5
B. 5.0
C. 4.8
D. 2.5
E. 2.4

The OA is C

Source: Princeton Review

We can use the formula: average rate = total distance/total time:

average rate = 24/(12/6 + 12/3) = 24/5 = 4.8

Answer: C