Question 1113365
<pre>
FAMILY        RATE         TIME       VOLUME
Scott         25           40-t       25(40-t)
Parker        40            t         40t
Total                      40          1375
</pre>


{{{25(40-t)+40t=1375}}}

-

{{{5(40-t)+8t=275}}}

{{{200-5t+8t=275}}}

{{{3t=75}}}

{{{highlight(t=25)}}}------hours, the Parker family
-
{{{highlight(15)}}}-------hours, the Scott family