SOLUTION: a person traveling 210 km by car drove the first part at 100 km/h and the rest at 80 km/h. If the trip took 2.25 h to complete, what distance was traveled at 100 km/h.

Question 162900: a person traveling 210 km by car drove the first part at 100 km/h and the rest at 80 km/h. If the trip took 2.25 h to complete, what distance was traveled at 100 km/h.
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
a person traveling 210 km by car drove the first part at 100 km/h and the rest at 80 km/h. If the trip took 2.25 h to complete, what distance was traveled at 100 km/h.
:
Let d = distance traveled at 100 km/h
:
The total distance is given as 210 km, therefore:
(210-x) = distance traveled at 80 km/h
:
Write a time equation: time =
:
100km/hr time + 80km/hr time = 2.25 hrs
+ = 2.25
:
Multiply equation by 400
400* + 400* = 400(2.25)
:
Cancel the denominator out and you have:
4d + 5(210-d) = 900
:
4d + 1050 - 5d = 900
:
4d - 5d = 900 - 1050
:
-d = -150
:
d = 150 km at 100 km/hr
then
210 - 150 = 60 km at 80 km/hr
:
:
Check solution by finding the times
150/100 = 1.5 hr
60/80 = .75 hrs
----------------
total hr 2.25
RELATED QUESTIONS
A person traveling 210 km by car drove the first part at 100 km/h and the rest at 80... (answered by richwmiller)

A person traveling 210 km by car drove the first part at 100 kph and the rest at 80 kph.... (answered by TimothyLamb,MathTherapy)

john drove part of a 260 km trip at 80 km/h and the rest at 100 km/h. find the distance... (answered by checkley71)

John drove part of a 260 km trip at 80 km/h and the rest at 100 km/h. Find the distance... (answered by ankor@dixie-net.com)

Sharon drove for part of a 150 km trop at 45 km/h and the rest of the trop at 75km/h. How (answered by ankor@dixie-net.com)

Dan drove from his farm to town, traveling the first 50 km at 80 km/h, and the next 30 km (answered by greenestamps,ikleyn)

4.Samantha drove 440 km in 5 hours. She drove part of the way at 80 km/h and the rest at... (answered by jorel555)

The total traveling time if the Smiths drove y km at 60 km/h and on the return trip... (answered by Alan3354,josgarithmetic)

Joe drove 210 km at 70 km/h and then another 210 km at 105 hm/h. It took Bill the same... (answered by mananth)