First, type in the chance of the event occurring. Then, type in the amount of times the event is being repeated. Then, this will give you the probability of the event happening at least once. This is useful for calculating chances of getting a rare reward in a game or something.
Note: The chance must be a decimal between 0 and 1. Also the number of repetitions must be a natural number! Thanks to @Harry-P-Ness for the idea on reddit. Thanks to @JackMeHoff for the exponent script. Thanks to @BenDover for the idea and help!