Permutations & Combinations

Skills

• Multiplication Principle
• Addition Principle
• Complementation Principle
• Rearrangements $n!$
• Choosing $\left(\genfrac{}{}{0px}{}{n}{r}\right)$
• Choose and arrange $\left(\genfrac{}{}{0px}{}{n}{r}\right)\times r!$
• Grouping
• Slotting