Question 1136936
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The "time" equation is


{{{585/(x + 20)}}} = {{{505/(x+10)}}}.


Cross multiply; then simplify and solve for x.


585*(x+10) = 505*(x+20)


x = {{{(505*20 - 585*10)/(585 - 505)}}} = 53.125 miles per hour.    <U>ANSWER</U>
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