Question 1074979
<pre>
               SPEED        TIME       DISTANCE

UP             7-c          3/(7-c)     3    

DOWN           7+c          3/(7+c)     3

Total                         2
</pre>

Sum of the times
{{{3/(7-c)+3/(7+c)=2}}}


Solve for c.




{{{c=2sqrt(7)}}}