A parameter is a local name for the argument supplied at a call. return gives the result back, so the caller can print it or calculate further. Here a ticket price gets a service charge. Change the call from ticket_total(10) to ticket_total(12) and notice the new total. The next exercise changes the function itself.
12, producing 14.Edit main.py, press Run to inspect the result, then Submit to check your change.
Change only the number inside ticket_total(...).