Question

What is the correct notation of permutation of $n$ different things taken $r$ at a time with or without repetition?

• A. ${}^n{P}_r$
• B. $P_r^n$
• C. $\text{P(n, r)}$
• D. ${}_r^{n}P$

Answer 1

Answer: (A), (B), (C), (D)

${}_r^{n}P$

Permutation of $n$ different things taken $r$ at a time with or without repetition can be written as ${}^n{P}_r$ or $P_r^n$ or $\text{P(n, r)}$ or ${}_r^{n}P$.

These all are the notation of ${}^n{P}_r.$