A player picks random cards from an ordinary card deck, without returning them to the deck. How many cards should he pick so as to get at least one ace with 70% probability?
The first card is drawn with a 1/13 or aprox. 7.69% chance of Ace.
The secound card compound with the first yelds an aprox. 15.53%.
The third an aprox. 23.5%
The fourth an aprox. 31.7%
The fifth an aprox. 40.0%
The sixth an aprox. 48.5%
The seventh an aprox. 57.2%
The eighth an aprox. 66.1%
The nineth an aprox. 75.2% So it would take nine cards
Posted by Luna
on 2006-08-18 17:01:00