回複：Fun Probability Question 來源: TCT

來源: 於 2009-11-09 23:37:50 [舊帖] [給我悄悄話] 本文已被閱讀：次

0.5*(1 - P[having 10k after n tosses]) ?

and

P[having 10k after 30 tosses]
= (30 choose 15)*(1/2)^30

P[having 10k after 100 tosses]
= (100 choose 50)*(1/2)^100

hehe