16.1 Introduction

Probability is a branch of mathematics measuring the likelihood of an event occurring on a scale from 0 (impossible) to 1 (certain). It quantifies uncertainty, with results often expressed as fractions, decimals, or percentages. The formula is:
\(
\text { Probability }=\frac{\text { Number of favorable outcomes }}{\text { Total number of possible outcomes }}
\)

Examples:
Coin Toss: A fair coin has 1 favorable outcome (heads) out of 2 total outcomes (heads/tails), resulting in a \(1 / 2\) or \(50 \%\) probability.
Dice Roll: Rolling a 4 on a six-sided die is \(1 / 6\).