Expert: Ahmed Salami - 7/5/2010

Question
Hi Ahmed. Would anyone's chances of winning the lottery be higher or lower if they played the same numbers each time or picked randomed numbers each time? Whatever answer you have, why do you think that is the answer?

Answer
Hi Sterling,
It wont really matter if you play the same numbers each time or picked randomly, the chance is always the same. This may seem counter-intuitive but two people; one who has just won the lottery and another who hasnt won in, say, ten years both have the same chance of winning in the next round. This is because the winning numbers are supposedly chosen randomly with no memory of previous selection.
As another example, consider a person who has just tossed a coin four times and gotten heads each time. You might want to believe that he is more likely to get a tail on the next toss, but the chances of getting a tail is still the same as that of getting a head. Again, this is because a coin holds no memory of what it showed up earlier.
Now, you wonder what it really means that the chances of getting a tail on a coin toss is 1/2 if there's no advantage even after four heads in a row, dont you?

Regards