Permutations and combinations 1 Instructions Click the button below to start. Each time you click, a different word will be generated. Practice until you can answer these sorts of questions reliably. Generate Question Question Letters of the word $1$ are arranged. Find the number of ways of arrangements if all the letters are used, and there are no restrictions, all the letters are used, and the letters $2$ and $2$ must not be next to one another, only three letters are used, only four letters are used. Show answer Answer $4$. $5$. $6$. $7$.