The likelihood of an event occurring. Expressed as a number between 0 and 1, or as a percentage between 0% and 100%

Any process that can be repeated and has a well-defined set of possible outcomes.

A single result of an experiment.

A collection of one or more outcomes.

The set of all possible outcomes of an experiment.

The probability of event A occurring.

1 or 100%

0 or 0%

Events that cannot occur at the same time.

The outcome of one event does not affect the outcome of another.

The outcome of one event affects the outcome of another.

P(A or B) = P(A) + P(B)

P(A or B) = P(A) + P(B) - P(A and B)

P(A and B) = P(A) * P(B)

P(A and B) = P(A) * P(B|A) (P(B|A) is the probability of B given A has occurred)

The probability of an event occurring given that another event has already occurred. P(A|B) = P(A and B) / P(B)

The event that A does not occur. Denoted as A' or A^c. P(A') = 1 - P(A)

A visual representation used to organize and calculate probabilities, especially for sequences of events.

A visual representation used to show the relationships between sets of events, particularly useful for illustrating mutually exclusive and non-mutually exclusive events.

The average outcome of an experiment over a large number of trials. Calculated by summing the product of each outcome and its probability.

An arrangement of objects in a specific order. nPr = n!/(n-r)!

A selection of objects where order does not matter. nCr = n!/(r!(n-r)!)

The product of all positive integers up to n. Example: 5! = 5*4*3*2*1 = 120