If there are 800000 tickets, and I use 2000 tickets, what is the % of me winning?

If there is only ONE winning ticket, when you buy 1 ticket you have a 1/800000 chance of winning.  Buy another ticket from the 79999 tickets remaining and you have a 1/79999 chance of winning....etc

So    1/800000 + 1/799999 + 1/799998 ..........1/798001   =   

         I think!    Can anyone 2nd that?

=

     

x 100 = .2503 %

If there is one winning ticket then you have 2000 chances to win out of a possible 800000 tickets.

$${\frac{{\mathtt{2\,000}}}{{\mathtt{800\,000}}}}{\mathtt{\,\times\,}}{\mathtt{100}} = {\frac{{\mathtt{1}}}{{\mathtt{4}}}} = {\mathtt{0.25}}$$  

That is 0.25% chance     (exactly 1 chance in 400)