At Least Once
If probability of an event happening is p, then the probability that the event happens at least once in n trials is 1-(1-p)∧n.
Example:
To understand the equation follow these steps:
1.The probability of the event not happening is 1-p.
2.The probability it won't happen n-times in a row is (1-p)∧n.
3.Probability it will happen at least once is 1-(1-p)∧n.
