The Probability Spectrum & Laplace's Rule
Lead Educator: Prof. Arvind Swaminathan (Senior NCERT Mathematics Faculty)
? Visual Concept Diagrams & Figures

1. Classical Probability Definition (Pierre-Simon Laplace, 1812)
If an experiment has $n(S)$ total, mutually exclusive, equally likely outcomes, and $n(E)$ of them are favourable to an event $E$:
2. The Universal Axioms
- The Probability Bounds:
(Probability cannot be negative, and cannot exceed 1).
- Impossible Event ($\phi$): An event that cannot possibly occur has $P(\phi) = 0$.
- Sure / Certain Event ($S$): An event that is guaranteed to occur has $P(S) = 1$.
- Complementary Events ($E$ and $\bar{E}$):
- Elementary Events Law: The sum of probabilities of all elementary outcomes of an experiment equals $1$:
