☆─────────────────────────────────────☆
szbill (风) 于 (Sun May 11 20:19:11 2008) 提到:
toss a coin 100 times, what's the probability at least 60 of them are heads?
☆─────────────────────────────────────☆
redvalley (cabbage) 于 (Sun May 11 20:47:40 2008) 提到:
0.0176