I need a thing, and I think I'm having trouble communicating it. I need the name of this thing, if it has one, the calculations behind it, and preferably an online tool where I can punch in two variables and get an answer.
It's the probability that, during a single event, variable A has a chance to happen. And the event repeats variable B number of times. What is the probability that, repeated B times, A will happen at least once? It can happen more than once, and you don't stop counting B if A occurs.
I'm having trouble thinking of what the calculation should be and it's super mega bothering me.
Okay I think I found it. Probability of something happening during an event is A. Number of times the event is repeated is B. Probability of event A occurring at least once when event is repeated B times is C.
1 - A ^ B = C
Such that if you flip a coin five times, the chance it will have landed heads at least once is 96.875%.
If you roll a d20 100 times, the chance you'll roll a 20 at least once is apparently too complicated a number for my calculator app to handle because it just says 1 and I know that's wrong.
Like a deck of 52 playing cards. Shuffle, and draw a card. The probability the card drawn is 7 of clubs is 1/52.
The truck is it's not additive. If you shuffle and draw 52 times, the probability you'll have drawn 7 of clubs at least once isn't 100%.