Probability Calculator

This calculator helps you compute probabilities for various scenarios using fundamental probability formulas. It can calculate simple probabilities, compound probabilities for independent and dependent events, and conditional probabilities.

1. 1

   Step 1

   Identify the type of probability problem (simple, compound, or conditional)

2. 2

   Step 2

   Enter the number of favorable outcomes and total outcomes

3. 3

   Step 3

   Select the probability operation (AND, OR, NOT)

4. 4

   Step 4

   Click calculate to get the probability result

5. 5

   Step 5

   Review the step-by-step solution and interpretation

• 1

  Probability values always range from 0 (impossible) to 1 (certain)

• 2

  The sum of all probabilities in a sample space equals 1

• 3

  Use the multiplication rule for AND probabilities of independent events

• 4

  Use the addition rule for OR probabilities, subtracting overlap for non-mutually exclusive events

• 5

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

• Confusing independent and dependent events when multiplying probabilities

• Forgetting to subtract P(A and B) when using the addition rule for non-mutually exclusive events

• Assuming events are independent without verification

• Confusing probability with odds - they are different concepts

• Not considering all possible outcomes in the sample space