Let \(p=\) the price of a ticket
Let \(c=\) the cost to put on the show
Formula:
(profit) = (ticket price) * (number of people) - (cost to put on show)
We have two equations here:
\(500=120p-c\)
\(400=100p-c\)
Solve:
\(100=20p\)
⇒\(p=5\)
⇒\(400=100(5)-c\)
⇒\(400=500-c\)
⇒\(c=100\)
So the price of a ticket is $5, and the cost to put on the show is $100.