Question 1063036
Constant Travel Rates Rule, RT=D  to relate rate, time, distance.
<pre>
               SPEED      TIME         DISTANCE
A to B          20        d/20          d
B to A           v        d/v           d
Totals                    d/20+d/v     2d

Average         24
</pre>

Average rate expression is  {{{(2d)/(d/20+d/v)}}} and the value is given.


{{{highlight_green((2d)/(d/20+d/v)=24)}}}
Simplify this and solve for v.