▲ 7 r/probabilitytheory+1 crossposts

Combinatorics problem (balls in bins)

Struggling currently with coming full circle on a problem. Given:

15 non unique bins n=15
6 non unique balls m=6
bins uniformly of size 4

What is the probability that 2 or more balls will end up in the same bin. Experimentally I know the result is about 59% and have the following formula to describe the situation

P(X>=2) = 1 - (((15c6)×4^(6))/(60c6))

However I am struggling with the derivation of the above, a breakdown from someone better at stats than I would be appreciated.

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u/FROG_TM — 6 days ago

True Trinket gaming

Cant wait to 8th because I have no money in the midgame oh god please help me balance my budget my family is starving.

u/FROG_TM — 7 days ago