Question 892755
x = long term members
y = new members
Immediately you can form {{{x+y=200}}}.


You say, "all new members buy a yearbook", at $20 each.
You say, too, "60% of long termers buy...", at $12 each .


{{{(60/100)12x+20*y=r}}}, using r for yearbook sales revenue.
{{{(3/5)12x+20y=r}}}


This is nearly all that can be done.  THREE unknown variables, but only two equations.  You could use the member count equation to put r either in terms of x or in terms of y.  You still have r as an unknown variable.  You know also that x, y, and r will be whole numbers.


What more is in the description?  Did you want maybe a graph of r versus x or y?