SOLUTION: In a three-person, 100-meter race,Amy finishes 10 meters ahead of Brooke and 20 meters ahead of Carol. Assuming constant speeds for each runner, by how many meters did Brooke finis

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Question 208716: In a three-person, 100-meter race,Amy finishes 10 meters ahead of Brooke and 20 meters ahead of Carol. Assuming constant speeds for each runner, by how many meters did Brooke finish ahead of Carol?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
In a three-person, 100-meter race,Amy finishes 10 meters ahead of Brooke and 20 meters ahead of Carol.
Assuming constant speeds for each runner, by how many meters did Brooke finish ahead of Carol?
:
Let t = A's time to run 100 meters
then
During this time; B ran 90m and C ran 80m
:
Find their speed: speed = Dist/time
:
90%2Ft = B's speed
and
80%2Ft = C's speed
:
Find B's time to run 100 yds (time = dist/speed)
B's time = 100%2F%2890%2Ft%29 = 100 * t%2F90%29 = %28100t%29%2F90 = %2810t%29%2F9
Find how far C runs in %2810t%29%2F9; (Dist = speed * time)
C's dist = 80%2Ft * %2810t%29%2F9
Cancel t:
80*%2810%29%2F9 = 800%2F9 = 88.89 ft
therefore
100 - 88.89 = 11.11 meters; C is behind when B crosses the finish line
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Hope this makes sense to you?