5 Trials (draws): 800 tickets to win one of 500 dolls and I buy 5 tickets

If there are 800 tickets to win one of 500 dolls and I buy 5 tickets what are my chances of winning a doll? I get that if I buy one ticket my chance would be 5/8, but can't figure out how to work in the 5 different tickets. (the lottery administrator will draw 500 of the 800 tickets, those drawn get a doll).

What would be my chance to win two dolls? Three?





Thanks, so my chance of getting at least one is 1-(.375)*5= 99.3%

Lucinda said:

If there are 800 tickets to win one of 500 dolls and I buy 5 tickets what are my chances of winning a doll? I get that if I buy one ticket my chance would be 5/8, but can't figure out how to work in the 5 different tickets. (the lottery administrator will draw 500 of the 800 tickets, those drawn get a doll).

What would be my chance to win two dolls? Three?

Click to expand...

This is one of those questions that I find it best to tackle as a 'I don't get a winning ticket'. Then the probability of getting a winning ticket is just one minus the probability of getting none. So, not to win is
1st buy = 300/800
2nd buy = 299/799
3rd buy = 298/798
...

Is this Bernoulli? With p=.625, q=.375, n=5 (tials), k=1(success)

5x.625 x(.375)*4

Lucinda

Is it Bernoulli?

K=1, N=5 p=.625 and q=.375

This really happened to me, there were 800 $20 doll art calendars made by the doll dealer (tickets) and not all sold. There were supposed to be 500 dolls supplied by the manufacturer. Me and others bought multiple calendars and did not win one doll.
It was a right to buy lottery, the dolls are expensive. The dealer was likely dishonest. I saw later the doll dealer selling hundreds on E-bay for 5 x retail for years.
He had an agreement with the manufacturer. Well, he was let go (as a dealer).

His friends won, and famous collectors. I was unkown. Some who won multiple put their second,third wins back. There were 4 draws.

(well so the math wont be exact)