Question 211430: A train travels at an average speed of 20 mph through urban areas, 50 mph
through suburban areas, and 75 mph through rural areas. If a trip consists of
traveling half an hour through urban areas, 3-1/2 hours through suburban areas,
and 3 hours through rural areas, what is the train’s average speed for the entire
trip?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! A train travels at an average speed of 20 mph through urban areas,
50 mph through suburban areas, and
75 mph through rural areas.
If a trip consists of traveling half an hour through urban areas,
3-1/2 hours through suburban areas,
and 3 hours through rural areas,
what is the train’s average speed for the entire trip?
;
Find the distance of the trip (dist = speed * time)
:
Total dist = urban dist + suburb dist + rural dist
d = (20*.5) + (50*3.5) + (75*3)
d = 10 + 175 + 225
d = 410 mi
:
Find the total time:
t = .5 + 3.5 + 3
t = 7 hrs
:
Av speed = 
s = 
s = 58.57 mph
;
:
Check solution, find the dist: 7 * 58.57 = 409.99 ~ 410
|
|
|
