7 people

Start with $160. and subtract $12 for parking because you have to pay that no matter how many people you buy tickets for.

160-12=148

Now you can see how many tickets you can buy with $148 by dividing by the price of the ticket which is $20.50

148/20.5=7.21951219512

You can buy 7 tickets

if you do the math, there is $4.50 leftover