Hi..Im new here..and yes Im looking for someone to help me with this problem...

There's a anual bingo game in my city, each player has a card with 15 numbers on it. The total of balls is 90.

Every year they sell about more of 20.000 cards, and always they getonly 1 winner...

I dont know how is this possible, when they assure that the extraction of the numbers is fully tranparent and without cheating.

They say that have a"secret formula"to make the cards for only 1 winner per time...

can someone tell me something about that "secret formula" to make cards and not to cheat in the extraction of the numbers??...or is it just a trap well covered...

thats all..

thanks!