Question 664161: a car traveled at an average rate of 65 miles per hour and then reduced its average rate ro 45 miles per hour for the rest of the trip . if the 180 mile trip took 3 hours, determine how long the car traveled at each rate?
what i came up with was 180-65=115/3 and got 38.33 and 180-45=135/3 = 45 but when i added the two they dont equal the same so im really lost
Answer by MathTherapy(10552)   (Show Source):
You can put this solution on YOUR website! a car traveled at an average rate of 65 miles per hour and then reduced its average rate ro 45 miles per hour for the rest of the trip . if the 180 mile trip took 3 hours, determine how long the car traveled at each rate?
what i came up with was 180-65=115/3 and got 38.33 and 180-45=135/3 = 45 but when i added the two they dont equal the same so im really lost
It can’t be done that way!!
Let time 1st part of trip took be T
Then 2nd part of trip took 3 – T
Distance traveled during 1st part of trip, plus distance traveled during 2nd part of trip, equals total distance traveled, OR
65(T) + 45(3 – T) = 180
65T + 135 – 45T = 180
65T – 45T = 180 – 135
20T = 45
T, or time taken on 1st part of trip, or at 65 mph =  , or  hours, or 2 hours, 15 minutes
Time taken on 2nd part of trip, or at 45 mph = 3 – 2.25, or  hour, or 45 minutes
See if you can do the check!!
Send comments and “thank-yous” to “D” at MathMadEzy@aol.com
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