Hi!

In scenario 4, question 2

" Each spectator also spends money parking and on concessions. The team owns both the nearby lots and the concession stands at the arena. The team has estimated that concession profits increase by $5 per person, and for every four spectators, one parking permit that is priced at $10 is purchased. With these new sources of revenue, what is the optimal ticket price?

The answer to the optimal ticket price is $13, with a revenue sum of 112.750. How did they find that as the answer?