Question 1184620
A and B, the amount of time of each plan


<pre>
                  Plan A           Plan B     total time hrs.

FRIDAY             3                   5             9

SATURDAY          12                   2             9
</pre>

Accounting for the time quantities in both days' workouts
{{{system(3A+5B=9,12A+2B=9)}}}
This should be clear and how to solve should be very routine and common.  Elimination Method may be best.