SOLUTION: evan drove halfway home at 20 miles per hour then sped up
and drove the rest of the way at 30 miles per hour.
what was his average speed for the entire trip?
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-> SOLUTION: evan drove halfway home at 20 miles per hour then sped up
and drove the rest of the way at 30 miles per hour.
what was his average speed for the entire trip?
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Question 310697: evan drove halfway home at 20 miles per hour then sped up
and drove the rest of the way at 30 miles per hour.
what was his average speed for the entire trip? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Evan drove halfway home at 20 miles per hour then sped up and drove the rest of the way at 30 miles per hour.
what was his average speed for the entire trip?
:
let a = average speed for the entire trip
:
Let d = half way distance
then
2d = entire trip
:
Write a time equation
time at 30 + time at 20 = total time + =
multiply by 60a, results:
2a(d) + 3a(d) = 60(2d)
:
2ad + 3ad = 120d
:
simplify, divide by d
2a + 3a = 120
5a = 120
a =
a = 24 mph is the av speed
