Probability Calculator

Calculate probabilities for two events including independent and dependent events.



Understanding Probability

Probability measures the likelihood of an event occurring, ranging from 0 (impossible) to 1 (certain).

Key Formulas:

  • P(A'): 1 − P(A)
  • P(B'): 1 − P(B)
  • P(A∩B): P(A) × P(B) (independent events)
  • P(A∪B): P(A) + P(B) − P(A∩B)
  • P(AΔB): P(A∪B) − P(A∩B)
  • P((A∪B)'): 1 − P(A∪B)
  • P(A but not B): P(A) − P(A∩B)
  • P(B but not A): P(B) − P(A∩B)