Question 78860
<pre>
                  SPEED      TIME       DISTANCE
firstportion       r         560/r       560
secondportion      r         480/r       480
difference                     1
</pre>


{{{560/r-480/r=1}}}-------solve for r, and evaluate {{{480/r}}}.


{{{80/r=1}}}

{{{highlight_green(r=80)}}}

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secondportion time, 6 hours