odds

[homer]

I've just kept my lottery tickets for the whole of april and over the period I managed not to get a single correct number . I do 2 lines each week , so what are the odds of such a run of BAD luck ?
Our lottery is 6 numbers from a possible 49 .
By the way I can draw the obvious conclusion , stop doing the lottery and save the £2 ....

 

[ceptimus]

You need to tell us whether the two tickets you buy for each draw ever share any numbers, before we can do the sums.

Do you have a total of 12 different numbers for each draw?

 

[Bjorn]

I might be confusing the numbers here, but if the two 'lines' are totally different (no numbers repeated) you are using 12 out of 49 numbers, and they pick a number 6 times.

I find that the chances of getting zero correct numbers in one week is about 16%, four weeks in a row about 0.076%. Did I screw it up somehow?

 

[BPSCG]

When the New York State lottery first came out in the 1960's I was about 15 years old and bought one of their once-a week tickets (that's all there was). Ticket cost a buck, which, for a fifteen-year old in 1966, was serious money.

The tickets, if I recall correctly, had the number pre-printed on it, and the number was six or seven digits long. I saved and cherished my ticket until the drawing day. The next day, I eagerly looked up the winning number in the paper, mentally spending my new wealth.

Not one digit that appeared ANYWHERE in my number appeared ANYWHERE in the winning number. It was as if my number was 0246864 and the winning number was 1357975.

I cursed softly, and realized my number could have been a LOT closer and I still would have lost.

I became much wiser that day. The following week, I started buying "Mad" magazine regularly, which was dedicated to teaching pimply-faced adolescents that the world is full of sharks looking to fleece you. A much better investment.

As regards lotteries, I live by two maxims:

If you don't play, you can't lose.
Your chances of winning are almost exactly the same whether you play or not.