A spider eats 3 flies a day. Until the spider fills his quota a fly has a 50% chance of survival if he attempts to pass the web.
Assuming 5 flies have already made the attempt to pass, what is the probability that the 6th fly will survive the attempt?
The fly (as well as any other fly that passes through before the spider is fed) has a 50% chance of survival... the previous flies cannot and will not affect the sixth's chances...
∞ Magick is not to be taken lightly...