How many permutations are there of the letters of the word Rattata?

This video demonstrates how to calculate the number of unique permutations for a word containing repeated letters, using 'RATTATA' as an example. It begins by calculating the total arrangements assuming all seven letters are distinct, which yields 7! (factorial). The presenter then explains that because there are three identical 'A's and three identical 'T's, these duplicate arrangements must be divided out. By dividing 7! by 3! twice (once for the A's and once for the T's), the final count of unique permutations is determined to be 140.

Before you watch

• Basic understanding of Factorials (!)
• Concept of Permutations/Arrangements