The Addition Rule in probability can feel tricky, especially when you’re trying to understand combined events.

Challenges:

• Many students have a hard time figuring out the difference between mutually exclusive events and non-mutually exclusive events.
• If the rule isn't applied correctly, it can lead to mistakes in calculations.

Simplification:

The Addition Rule makes things easier by offering a simple way to figure it out:

• For mutually exclusive events (events that cannot happen at the same time):

  • You can calculate the probability by using this formula:
    P(A or B) = P(A) + P(B).

• For non-mutually exclusive events (events that can happen at the same time):

  • Use this formula:
    P(A or B) = P(A) + P(B) - P(A and B).

By following these formulas step by step, students can clear up their confusion.