Question 67731
Steve leaves Nashville to visit his cousin David in Napa 80 miles away. He travels at an average speed of 50 m/hr. Half an hour later, David leaves to visit Steve traveling at an average speed of 60 m/hr. How long after David leaves will they meet? 
:

When they do meet they will have traveled a total of 80 mi
:
Let t = David's time
Then (t+.5) = Steve's time (he left a half hour earlier)
:
Distance = speed * time
Steve's distance: 50(t+.5)
David's distance: 60t
:
Steve's distance + David's distance = 80
50(t+.5) + 60t = 80
:
50t + 25 + 60t = 80
110t = 80 - 25
110t = 55
t = 55/110
t = .5 or half an hour
:
:
Check our solution
Steve would be driving for 1 hr and david for a half hour:
(50 * 1) + (60 * .5) = 80