Question 559581: At 1:00 p.m. a car leaves St. Louis for Chicago, traveling at a constant speed of 65 miles per hour. At 2:00 p.m. a truck leaves Chicago for St. Louis, traveling at a constant speed of 55 miles per hour. If it is a 305-mile drive between St. Louis and Chicago, at what time will the car and truck pass each other?
I'm having trouble with this because of the different times that the vehicles left. Thanks!
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! At 1:00 p.m. a car leaves St. Louis for Chicago, traveling at a constant speed of 65 miles per hour.
At 2:00 p.m. a truck leaves Chicago for St. Louis, traveling at a constant speed of 55 miles per hour.
If it is a 305-mile drive between St. Louis and Chicago, at what time will the car and truck pass each other?
:
Let t = travel time of the truck that leaves at 2 PM
then
(t+1) = travel time of the car which left at 1 PM
:
When the two meet, the distance each traveled will add up to 305 mi
:
Write a distance equation, dist = speed * time
car dist + truck dist = 305 mile
65(t+1) + 55t = 305
65t + 65 + 55t = 305
65t + 55t = 305 - 65
120t = 240
t = 240/120
t = 2 hrs, is the travel time of the truck which left at 2 PM
therefore
2 PM + 2 hrs = 4 PM they will meet
:
:
We can prove this
Car travel time = 3 hrs
3*65 = 195
2*55 = 110
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total: 305
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