Chance to win a drawing

#1
Hello,

We had a disscussion at work, so tell me what you think.

There are 4 available concert tickets and 10 people applied to get them. If each person cant win more than 1 ticket, what is the probability that you will win a ticket? I say 40% because based on every single possible outcome, 40% win and 60% lose everytime. He says 47.8 or 1/10+1/9+1/8+1/7 but i dont think that's the case here since you would be out of the running if you were pulled on the first or second try etc? Can someone help explain the right answer?

Thank You!
-Tyson Andrews
 

Dason

Ambassador to the humans
#2
You are correct.

One of my preferred ways to go about replying to the kind of logic that the other person conveyed is by asking them to go further with it. If there were 9 tickets for ten people what is the probability that you will win a ticket? Let them use their same logic - after all if their logic is sound then it should work here as well. Applying their logic gets you an impossible answer which (hopefully) tips them off that they made an error in their reasoning.