If A and B are any two mutually exclusive events, then P ( A ∪ B ) = P ( A ) + P (B) Probability is a measure that is associated with how certain we are of outcomes of a particular experiment or activity.

Three ways to represent a sample space are: to list the possible outcomes, to create a tree diagram, or to create a Venn diagram. If the result is not predetermined, then the experiment is said to be a chance experiment.

Probability — a number between zero and one, inclusive, that gives the likelihood that a specific event will occur; the foundation of statistics is given by the following 3 axioms (by A.N…. Event — a subset of the set of all outcomes of an experiment; the set of all outcomes of an experiment is called a sample space and is usually denoted by S . An event is an arbitrary…. Mutually Exclusive — Two events are mutually exclusive if the probability that they both happen at the same time is zero. If events A and B are mutually exclusive, then P ( A ∩ B ) = 0. Tree Diagram — the useful visual representation of a sample space and events in the form of a “tree” with branches marked by possible outcomes together with associated probabilities….

Be able to find the probability of getting at least one (one or two) tail in two flips. Let F = event of getting at least one tail in two flips. F = { HT , TH , TT }. P…; find P ( B | D ); find P ( D | B ).