SOLUTION: two cars left daisy's diner at the same time and traveled in opposite directions. one car traveled for 78 minutes. the other car traveled for 144 minutes at a rate of 5 km/h faster

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Question 1006688: two cars left daisy's diner at the same time and traveled in opposite directions. one car traveled for 78 minutes. the other car traveled for 144 minutes at a rate of 5 km/h faster than the first car. if the faster car went twice as far as the slower car, how fast did each car travel?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
two cars left daisy's diner at the same time and traveled in opposite directions.
one car traveled for 78 minutes.
the other car traveled for 144 minutes at a rate of 5 km/h faster than the first car.
if the faster car went twice as far as the slower car, how fast did each car travel?
L
let s = speed of the 1st car
then
(s+5) = the speed of the 2nd car
:
Since we are using km per hr, we have convert the minutes to hrs
dist = time * speed
2nd car dist = twice 1st car dist
144%2F60*(s+5) = 2(78%2F60 * s)
multiply both sides by 60
144(s+5) = 2(78s)
144s + 720 = 156s
720 = 156s - 144s
720 = 12s
s = 720/12
s = 60 km/hr speed of the 1st car
then obviously,
65 km/hr is the speed of the 2nd car
:
:
Check this by finding the actual distance each traveled
144%2F60 * 65 = 156 km
78%2F60 * 60 = 78 km, half as far