<PRE><B>Question 199</B>
Airline&#39;s revenue is: Number of passengers * ticket price. &lt;BR&gt;

Number of passengers also depends on ticket price:&lt;BR&gt; 

Number of passengers = 2,000 - 50 * (ticket price - 100)/10&lt;BR&gt;

So, airline&#39;s revenue is:&lt;BR&gt;

(2,000 - 50 * (ticket price - 100)/10)*ticket price&lt;BR&gt;

Denote ticket price as x&lt;BR&gt;

Revenue = (2000-50*(x-100)/10)*x&lt;BR&gt;

When you simplify it, you get a quadratic expression, that you can plot on my site.&lt;BR&gt;</PRE>