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

MCQ

The value of 2 × 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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