Simple Probability

The probability of a single event occurring.

Example: Rolling a 4 on a six-sided die: P = 1/6 ≈ 0.167 or 16.7%

Compound Probability

The probability of two or more events occurring.

• AND (Independent): P(A and B) = P(A) × P(B)
• OR (Mutually Exclusive): P(A or B) = P(A) + P(B)

Conditional Probability

The probability of an event occurring given that another event has occurred.

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

Coin Flip

P(Heads) = 1/2 = 0.5 = 50%

Two equally likely outcomes

Drawing a Card

P(Ace) = 4/52 ≈ 0.077 = 7.7%

4 aces in a 52-card deck

Two Dice Sum

P(Sum = 7) = 6/36 ≈ 0.167 = 16.7%

Six ways to get 7 out of 36 outcomes

Weather Forecast

P(Rain) = 0.3 = 30%

Based on historical data and models