A man walks from B to C, a distance of x miles, at 6 miles per hour and returns at 12 miles per hour. What is his average speed? Choose the correct choice from the following answers: A) 10 mph B) 9.6 mph C) 8.0 mph D) 8.4 mph E) 4 mph
Total distance covered = 2x   Time taken12miles / hour = x/12 hrs   Time taken @ 6 miles / hour = x/6 hrs   Avg speed = 2x / (x/6 + x/12) = 8 mph   Ans is 8.0 mph
<result>C</result>
A man walks from B to C, a distance of x miles, at 6 miles per hour and returns at 12 miles per hour. What is his average speed?