Probability notation

• P(A) = the probability of A
• P(A U B) = the probability of A or B (or both).
• P(A n B) = The probability of A and B.
• P(A') = the probability of not A.
• P(A | B) = the probability of A given B occurs.
• The addition rule


  P(A U B) = P(A) + P(B) - P(A n B)
• The given rule

  P(A | B) = P(A n B) / P(B)