Question 194340
David travels for 6 hours at a rate of 50 mph. 
his return trip takes him 7.5 hrs.
 what is his average speed for the whole trip?
:
Find the one-way distance (dist = time * speed):
6*50 = 300 mi
:
The round trip dist: 2 * 300 = 600 mi
:
The total time for the round trip: 6 + 7.5 = 13.5 hrs
:
Average speed = {{{dist/time}}}
Av speed = {{{600/13.5}}} = 44.44 mph