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Section2The Additive Principle

Definition2.1Additive Principle

The additive principle states that if event \(A\) can occur in \(m\) ways, and event \(B\) can occur in \(n\) disjoint ways, then the event “\(A\) or \(B\)” can occur in \(m + n\) ways.

See DDOI, Section 1.1

The key to this definition is understanding what disjoint means. Simply put, two events are disjoint if they cannot both occur in the same context.

Example2.2Disjoint events
Example2.3Disjoint and non-disjoint events
Exercise2.4When can we use the Additive Principle?
Exercise2.5Using the Additive Principle

Use the Additive Principle to solve these problems.