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Question 662212: Behnaz and Hannah were visiting a friend in Chicago. Behnaz has to leave at noon, but Hannah did not leave for another 1 hours. On the road, Behnaz averages 45 miles per hour and Hannah averages 55 miles per hour. They left from the same point (their friends house), however they drove off in opposite directions. How long would Behnaz have been driving when they will be 495 miles apart?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Behnaz and Hannah were visiting a friend in Chicago.
Behnaz has to leave at noon, but Hannah did not leave for another 1 hours.
On the road, Behnaz averages 45 miles per hour and Hannah averages 55 miles per hour.
They left from the same point (their friends house), however they drove off in opposite directions.
How long would Behnaz have been driving when they will be 495 miles apart?
:
let t = B's travel time
then
(t-1) = H's travel time
:
Write a distance equation: dist = speed * time
B's dist + H's dist = 494 mi
45t + 55(t-1) = 495
:
45t + 55t - 55 = 495
100t = 495 + 55
100t = 550
t = 550/100
t = 5.5 hrs, is B's travel time when they are 495 mi apart
:
:
Check this by finding the actual dist each traveled
45(5.5) = 247.5 mi
55(4.5) = 247.5 mi
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tot dist: 495 mi
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