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Calculatrice de Probabilité

Calculer les probabilités, chances et combinatoire

Dernière vérification : Précision vérifiée
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Probability Formulas

P(A) = favorable / total

P(A and B) = P(A) × P(B) (independent)

P(A or B) = P(A) + P(B) - P(A and B)

C(n,r) = n! / (r! × (n-r)!)

P(n,r) = n! / (n-r)!

Sources et méthodologie
Formule : P(A) = Number of favorable outcomes / Total outcomes

Basic probability calculation

Source : Standard probability theory

How to Calculate Probability

The Probability Calculator helps you find the likelihood of events occurring. Calculate simple probability, combinations, permutations, and expected value. Essential for statistics, gaming, gambling odds, and decision-making.

Basic Probability Formula

Probability = (Favorable Outcomes) / (Total Possible Outcomes). A probability of 0 means impossible, 1 means certain. Express as a fraction, decimal, or percentage.

Key Probability Concepts

  • Single event: P(A) = favorable / total outcomes
  • AND (both events): P(A and B) = P(A) × P(B) for independent events
  • OR (either event): P(A or B) = P(A) + P(B) - P(A and B)
  • NOT (complement): P(not A) = 1 - P(A)

Combinations vs Permutations

Combinations (order doesn't matter): How many ways to choose r items from n? C(n,r) = n! / (r! × (n-r)!)

Permutations (order matters): How many arrangements of r items from n? P(n,r) = n! / (n-r)!

Related Calculators

Generate random numbers with our random number generator. Analyze statistical significance with the p-value calculator. Find percentages for probability conversions.

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