Question 1180633
I think you mean 2 fewer people, not 20, because if the ticket sales are $30.25 and 380 people attend, one will be losing money, compared to 400 and $30.
Let x is number of $0.25 increase and multiples of 2 people.
(400-x)(($30+0.25x)
=12000-30x+100x-5x^2
the maximum is at x=-b/2a for this negative quadratic of -5x^2+70x+12000
this is x=70/10=7
so at $31.75 (7*$0.25-$1.75) and 386 people  (400-7*2)
there is a maximum, or $12,255.50
{{{graph(300,300,-5,10,-500,14000,-5x^2+70x+12000)}}}