SOLUTION: If r is the rate for one leg of a round-trip and s is the rate for the return trip, express the average rate for the round-trip in terms of r and s.

Question 813314: If r is the rate for one leg of a round-trip and s is the rate for the return trip, express the average rate for the round-trip in terms of r and s.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
If r is the rate for one leg of a round-trip and s is the rate for the return trip, express the average rate for the round-trip in terms of r and s.
-----
1st leg DATA:
rate = r units/hr ; time = x hrs ; distance = r*t = rx units
-------------
2nd leg DATA:
rate = s units/ hr ; distance = rx ; time = d/r = rx/s hrs
-----------------------
Average rate = total distance/total time
----
= [2rx)/[x + (rx/s)]
-----
= 2rx/[sx+rx)/s]
------
= 2rx
------
= 2rs/(s+r) units/hr
=======================
Cheers,
Stan H.
==================

RELATED QUESTIONS
You commute to work a distance of 80 miles and return on the same route at the end of the (answered by ankor@dixie-net.com)

Hyacinth hiked 7 miles from A to B at a rate of r mph. For the return trip her rate was 2 (answered by josgarithmetic)

A SIGHTSEEING BUS TRAVELS 40 MILES TO A SCENIC OVERLOOK. THE RATE RETURNING IS TWICE THE... (answered by josgarithmetic,MathTherapy)

1) A Commuter bus takes 2 hours to get downtown: an express bus, averaging 25mph faster,... (answered by Paul)

A jet flies from New York to Atlanta at an average rate of 420 mph. On the return trip,... (answered by jim_thompson5910)

You commute to work at a distance of 40 miles and return on the same route at the end of... (answered by ikleyn)

A man travels for 11 hours at the rate of 40 kph. His return trip took him 9 hours. What... (answered by flame8855)

David travels for 6 hours at a rate of 50 mph. his return trip takes him 7.5 hrs. what is (answered by ankor@dixie-net.com)

Won Young travels for 6 hours at a rate of 50 mph. His return trip takes 7.5 hours. What... (answered by Alan3354)