Reasoning
Combination
Count selections where order does not matter.
ⁿCᵣ = n! / [r!(n-r)!]
Formula Explanation
Combination counts ways of selecting r objects from n distinct objects without considering order.
Variables Explained
n = Total objects; r = Selected objects.
Solved Example
Choose 2 students from 5 students.
⁵C₂ = 5! / (2!3!) = 10.