# [plt-scheme] HtDP > Chapter 2 > Exercise 2.3.3.

Hello,
The problem says,
"An old-style movie theater has a simple profit function. Each
customer pays $5 per ticket. Every performance costs the theater $20,
plus $.50 per attendee. Develop the function total-profit. It consumes
the number of attendees (of a show) and produces how much income the
attendees produce."
I understand the problem but I cannot get it to work (not calculate
correctly) in DrScheme.
Here is my working progress:
(define(total-profit attendee)
(- 0
(- 20 0
(* 0.5 attendee)
(+ 0
(* 5 attendee)))))
Any ideas on what I am doing wrong? I might be miscalculating so tell
me if its right.
Thank you,