Depending on the number of prizes you have, you pick the same amount of people with the highest number. It can be alot of fun. For example:
Everyone starts with 100 points for being there. Then start with questions like:
If you are wearing gold earrings add 5 points
If you are wearing socks substract 10 points
If you have a condom in your bag plus 20 points
If you have a library card add 30 points
If you are wearing more than one ring substract 15 points
If you were born in the year 19## add 25 points
The questions are endless and can be a riot depending on the crowd.
Have fun with it.