<PRE><B>Question 747653</B>
 Starting from home,James traveled uphill to the office supply store for 75 minutes for 4 mph. He traveled back home along the same path downhill at a speed of 12 mph. What is the average speed for the entire trip from home to the office supply store and back? 
----
Uphill DATA:
rate = 4mph : time = 75/60 = (5/4) hrs ; distance = r*t = 4(5/4) = 5 miles
-------------------
Downhill DATA:
rate = 12 mph ; distance = 5 miles ; time = d/r = 5/12 hr 
------
Average speed = (total distance)/(total time) = 10 miles/[(5/4)+(5/12)] hrs
----
= 10/(15+5)/12 = 10/[20/12] = 120/20 = 6 mph
------------------------------
Cheers,
Stan H.
=========================
</PRE>