Calling mathematicians.

[jd_uk]

How many weeks will it take me on average to win a lottery if:

There is a draw once per week. I choose the same one ball out of a possible 49 balls every week. However there are only 19 people involved in the lottery draw who each also have chosen one ball so there is only a 19/49 chance of somebody winning each week. If nobody wins then the prize money rolls over.

 

[needtogetarmy]

How many weeks will it take me on average to win a lottery if:

There is a draw once per week. I choose the same one ball out of a possible 49 balls every week. However there are only 19 people involved in the lottery draw who each also have chosen one ball so there is only a 19/49 chance of somebody winning each week. If nobody wins then the prize money rolls over.

If there is one draw per week, and you play once per week, you should win the lottery once every 49 weeks. For example, in week one you have 1/49th chance of winning. In week two, regardless if someone won in week one (even if you won in week two), your chances of winning are still 1/49. Now your chances of winning in both weeks one and two are 1/2401, but that is a different issue all together.

In sum, the number of people playing, and the chances of the lottery rolling over etc., are independent events that are not related to the chance of you winning.

 

[GUARDIAN]

How many weeks will it take me on average to win a lottery if:

There is a draw once per week. I choose the same one ball out of a possible 49 balls every week. However there are only 19 people involved in the lottery draw who each also have chosen one ball so there is only a 19/49 chance of somebody winning each week. If nobody wins then the prize money rolls over.

u still only have a 1/49 chance every week as long as the winning ball is returned to the draw everytime. all of these drawings all mutually exclusive events. U cannot simply calculate an average number of weeks it takes to win.

 

[Smurfy]

u still only have a 1/49 chance every week as long as the winning ball is returned to the draw everytime. all of these drawings all mutually exclusive events. U cannot simply calculate an average number of weeks it takes to win.

preach it@!

 

[nimbus]

does the lottery end once somebody wins the prize? ignoring the prize, and expected pay out for now, each person should win the lottery once every 49 weeks. But that is not a sure thing. If you wanna know the odds of you winning within N weeks, the formula is

N/49*(48/49)^(N-1)