Question 606073
    Two mopeds leave town at the same time in opposite directions. One travels 25 kilometers per hour and the other one travels at 45 kilometers per hour. In how many hours will they be 210 miles apart?
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Apply the "distance formula" of d=rt:
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Let x = time (hours) driving
then
25x + 45x = 210
70x =  210
x = 210/70
x = 3 hours