Question 1094530
<pre>
            SPEED        TIME             DISTANCE

CAR         r+30         {{{500/(r+30)}}}        500

TRAIN       r            {{{300/r}}}             300
</pre>

Times are given as equal.

{{{500/(r+30)=300/r}}}

-

{{{5/(r+30)=3/r}}}


{{{3r+90=5r}}}


{{{90=2r}}}


{{{highlight(r=45)}}}-------speed of train