Question 618308: 2. 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! 2. 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 total travel time
.5 + 3.5 + 3 = 7 hrs
:
Let a = average speed for the entire speed
:
Write a distance equation, dist = speed * time
:
7a = 20(.5) + 50(3.5) + 75(3)
7a = 10 + 175 + 225
7a = 410
a = 410/7
a = 58.57 mph average speed
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