SOLUTION: Dana has 3 hours to spend training for an upcoming race. She completes her training by running full speed the distance of the race and walking back the same distance to cool down.

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Question 1153889: Dana has 3 hours to spend training for an upcoming race. She completes her training by running full speed the distance of the race and walking back the same distance to cool down. If she runs at a speed of 10mph and walks back at a speed of 2mph, how long should she plan to spend walking back?

Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
x, the speed walking back 
           SPEED        TIME         DISTANCE

RUN          10          3-x            d

WALK          2          x              d

Total                    3

highlight_green%2810%283-x%29=2x%29
-
5%283-x%29=x
15-5x=x
15=6x
5=2x
highlight%28x=2%261%2F2%29hourswalking

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The distances are the same; the ratio of the speeds is 10:2 = 5:1.

That means the ratio of times is 1:5.

That means the time spent running is 1/6 of the total time and the time spent walking back is 5/6 of the total time.

ANSWER: Time spent walking back = 5/6 of 3 hours = 2.5 hours.