The value of 2 P(n, n - 2) is: - Vidyadip

MCQ

The value of $2 \times P(n, n - 2)$ is:

A
$n$
B
$2n$
✓
$n!$
D
$2n!$

✓

Answer

Correct option: C.

$n!$

Given, $ 2\times\text{P}(\text{n}, \text{n} – 2)$
$= 2\times\frac{\text{n!}}{(\text{n} – (\text{n} – 2))}$
$= 2\times\frac{\text{n!}}{(\text{n} – (\text{n}+2))}$
$= 2\times\big(\frac{\text{n!}}{2}\big)$
$= \text{n!}$
So, $ 2\times\text{P}(\text{n}, \text{n} – 2)=\text{n}!$

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