It takes Joey the postman 1 hours to run a 4 mile long route every day. He delivers packages and then returns to the post office along the same path. If the average speed of the round trip is 5 mile/hour, what is the speed with which Joey returns?
Choose the correct choice from the following choices: A) 5 B) 12 C) 13 D) 14 E) 15
let his speed for one half of the journey be 4 miles an hour   let the other half be x miles an hour   now,   avg speed =5 mile an hour   2*4*x/4+x=5   8x=4x+20=&gt;x=5   5
<result>A</result>
It takes Joey the postman 1 hours to run a 4 mile long route every day. He delivers packages and then returns to the post office along the same path. If the average speed of the round trip is 5 mile/hour, what is the speed with which Joey returns?