SOLUTION: Chris and Pat exercise together by running opposite directions around a 108m circular track for 45 minutes. Starting together, Chris’ velocity is 5 2/3 meters per second while Pa

Algebra ->  Circles -> SOLUTION: Chris and Pat exercise together by running opposite directions around a 108m circular track for 45 minutes. Starting together, Chris’ velocity is 5 2/3 meters per second while Pa      Log On


   



Question 1150457: Chris and Pat exercise together by running opposite directions around a 108m circular track for 45 minutes. Starting together, Chris’ velocity is 5 2/3 meters per second while Pat runs 3 1/3 m/s. How many times do they pass one another in 45 minutes?
Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
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For the first time, they will meet each other, when the sum of the distances they cover will be exactly the length of the track


    52%2F3.t + 31%2F3.t = 108  meters,   or


    (52%2F3 + 31%2F3).t = 108

    9t = 108

     t = 108%2F9 = 12 seconds.


So, for the first time they will meet each other in 12 seconds.


After that, they are in the same situation, as originally: they start from the common point and move 

in opposite directions, with the same rates as before.  Hence, they meet each other again in 12 seconds next time.


Now it should be clear to you that they will meet each other EVERY 12 seconds.


So, to get the answer, you should divide 45 minutes by 12 seconds -- in this way you will get 


    45 minutes divided by 12 seconds = 45 minutes divided by 1%2F5 of the minute = 45*5 = 225 times.


ANSWER.  225 times. 

         We do not count the starting point.

         We count their last meeting at the end of the 45-th minute.

Solved.