Math geeks, help me out with this one?

[Airdive.2613]

@Ensign.2189 said:

@"Airdive.2613" said:I'm not sure this is correct.My thinking would be that regardless of which one unique item is missing, if you choose the starting point in our calculations as "

there is only one unique item missing

", then the event "

there is no [item] drop in 177 trials

" is exactly the same. Point being, as you're opening your chests one by one, there will always be "one last item" missing.Intuitively, it just shouldn't take you this many chests to get your desired last item. (I'm not judging the design itself, just talking about numbers.)

The probability of not getting a guild ballista after 177 trials is 0.0178%, as mentioned above. However the probability of not getting a guild treb is also 0.0178%, and probability of not getting a guild catapult, etc. So if you were looking for the probability of not having a complete set after 177 opens, that would be 1-(1-(20/21)^177)^21, which is the .37% number above.

And this seems to be correct if there were really 177 chests for the whole experiment. :)You can get 21^177 different outcomes in total, but what you need to get (to start this thread) are 21 outcomes that consist of 20^177 combinations. 21x(20/21)^177 is indeed 0.373%.

[Guest]

I have continued to try, maybe another 30-40 chests, still no luck. My drops so far seem to confirm what someone guessed earlier, that the Guild seige is lower chance than the other types, which all seem to be roughly equal, at about 50% of the chance of the others. (I have 4-5 of each type of guild siege except ballista, and 7-11 of all other types)

My sorrow continues; I will update when/if I ever get it with final stats...