2011-01-07, 04:06 AM
shouri Wrote:P(B|A)= P(BnA)/P(A)
P(HH|at least 1 head) = P(HHnat least 1 head)/P(at least 1 head)
p(HH n at least 1 head ) = P(HH) (since {HH} is contained in {at least 1 head})
P(HH) = 1/4
P(at least 1 head) = 3/4
P(HH)/P(at least 1 head) = (1/4) / (3/4) = 1/3.
But how do you find out if one of them is heads?

