Question 1165976
15 minutes is {{{1/4}}} hour.
25 minutes is {{{5/12}}} hour.

<pre>
             SPEED          TIME          DISTANCE
RIDE TO        r+8          {{{5/12}}}        d
WALK Back      r           {{{1&1/4}}}        d 
</pre>
This is not the only way, but the distances d being equal each way,
{{{(r+8)*(5/12)=(r)(1&1/4)}}}
Solve this for r, and then evaluate {{{(5/4)r}}}.