Probability of winning?

Question

In Hungary (population: 10 million) there is a chance to win an Apple Macbook. You have to buy a kind of beer :) and on the back of the label of each bottle there is a code that you can send in through the internet.

Before the game started, a computer randomly selected two dates (days, hours, minutes, maybe seconds as well) a week. If you send your code exactly at the selected times, or you are the first after the selected dates, you win (i.e. you can win two Macbooks every week).
This game lasts for four more weeks. The beer is Stella Artois, which is relatively expensive here, so it is not for the masses.

I am curious, how many codes do I have to send them every day so it becomes VERY likely that I win a Macbook?

You can buy the beer with codes only in hypermakerts like Tesco and Auchan. It might increase the chances :)

Answer 1

I would think that your best chances would be during the times of fewest submissions per minute, unless the computer never picks those times, which you have no way of knowing.

I think I would save up all my submissions for the last week, and divide them equally according to time. For example, if I had collected 100 codes, I would divide the number of minutes in a week (10080) by 100, getting 100.8, and therefore submit one code every 100 minutes, 48 seconds.

If you "feel lucky", pick one or two days that you think won't be picked, or maybe 2 hours out of each day that won't be picked, or both, and redivide into the remaining time, which of course, will then be more often. I'd take out the hours each evening between say 6 and 9 PM, since that's likely to be the heaviest traffic hours anyway.

Answer 2

To calculate probabilities, you need to estimate how many people in total are entering the competition, and have some idea how their entries are distributed over time.