Question 1169348
<pre>
PRICE       QTY       REVENUE
100         40         (100)(40)
100-10      40+5        (100-10)(40+5)
.
.
100-x      40+x/2      (100-x)(40+x/2)
</pre>
{{{R(x)=(100-x)(40+x/2)}}}  for each dollar decrease in price x.


Middle of the two roots is at x=10, for maximum revenue.


Price for max. revenue, 90Php.