If i have understood your question correctly you are trying to find out how many tickets you should buy in order to reach the hit 100% chance of winning. The answer is that you can never hit 100%, in order to do so you would need to own every single ticket but this is impossible as there are thousands of other users that have tickets. You can get very high chance if you buy thousands of tickets but this would be a very bad investment. It is a matter of luck, and i would advice you to buy some (perhaps little more than others if you enjoy gambling), but remember to keep for fun. Even playing dice is better way of earning extra coins rather than buying tickets.