Question 1043676
<pre>
PRICE          ATTENDANCE
2                100
2+1(0.1)         100-1
2+n(0.1)         100-n
</pre>


Revenue is price multiplied by number attended;
{{{r=(2+0.1n)(100-n)}}}, revenue as function of n attendees.


Think about that function and you should recognize it is of a parabola with vertex as a maximum.  The roots or zeros of r are  -20  and 100.  The vertex, max point, will be at the n value in the exact middle of the two roots.


What is r when n=40?
What is the admission price when n=40?