This is a for real raffle, 129000 tickets will be sold, 7400 prizes will be awarded. If you

Buy one ticket, you have a 1 in 18 chance of winning a prize. If I bought 3 tickets, would

The odds change very much or still be about the same ?

Thanks in advance for responding!!

If you buy 3 tickets your odds of winning at least one prize do indeed go up, by almost a factor of 3. Of course it costs you 3 times as much to play. The way to figure this out is to calculate the odds of winning at least one prize, which is equal to one minus the odds of not winning any prize. The odds of any one ticket being a loser is 121600/129000,or about 94.3%. So the odds of all three tickets being losers is 0.943^3 = 83.8%. Subtract that from 1, and you find that the odds of winning at least one prize is 1 - .838 = 16.2%. This is a little less than 3 times the odds of winning if you buy only 1 ticket - the reason it's less than 3 times is that you have a small chance of actually winning two prizes, or even 3.