Quote:
Originally Posted by guy1932
does the equation for propability that over 100 trials we won't get dealt any card of clubs or spades goes like this?
100% - 1/2 square(x)
where x is a number of trials?
In general if you have N trials and you want to know the probability of something that occurs with probability P (independently in each trial) occurring in exactly X of the trials the formula is
(N choose X) * P^X*(1-P)^(N-X)
In your case, N is 100 and X is 0 and P is (depending on whether you mean out of 2 cards or 1) either 1/2 or 25/102 as McNasty said (and of course his calculation is exactly right).
In general all this type of stuff is part of the binomial distribution which is worth reading about briefly:
http://en.wikipedia.org/wiki/Binomial_distribution
