Question 1139188
<pre>
              SPEED        TIME(hours)          DISTANCE

ACTUAL           r         {{{120/r}}}               120

IF              r+18       {{{120/(r+18)}}}          120
</pre>

{{{120/r-120/(r+18)=15}}}


-

{{{8/r-8/(r+18)=1}}}

{{{8(r+18)-8r=r(r+18)}}}

{{{8r+8*18-8r=r^2+18r}}}

{{{8*18=r^2+18r}}}                     

{{{r(r+18)=144}}}

{{{system(r=6,and,r+18=24)}}}


{{{highlight(r=6)}}}