Question 1033438
The description is of two problems.  The tourist boat is doing two round trips.  This is a data table for the 36 distance trip which is a 72 km round trip.  <s>The 60 km, 10 one-way is a separate problem and should be simpler to solve.</s>

<pre>
                     speed       time        distance

Going, downriver      r+c        36/(r+c)    36

Return, upriver       r-c        36/(r-c)    36

TOTAL                            8</pre>


Basic Rates Rule and sum of times gives  {{{36/(r+c)+36/(r-c)=8}}}, and you will need the other part of the description to analyze and them form an additional equation.  You will have two equations then, and two unknowns of r and c.


<pre>
                   RATE      TIME       DISTANCE
GOING (UPRIVER)    r-c       10          60
RETURN             r+c      not needed not given
</pre>
{{{(r-c)*10=60}}}



System of equations to solve is  {{{system(36/(r+c)+36/(r-c)=8,10(r-c)=60)}}}.