Question 1017296
<pre>
                   speed     time
freeway            r         3
country            r-20      3
TOTAL              306
</pre>

The description is very strange. "Total speed".

{{{r+(r-20)=306}}}
{{{r+r-20=306}}}
{{{2r-20=306}}}
{{{r-10=153}}}
{{{highlight(highlight(r=163))}}}------The freeway speed, so the country road speed was {{{highlight(r-20=143)}}}.