Q. 95.0( 6 Votes )

# If P(n – 1, 3) : P(n, 4) = 1 : 9, find n.

Answer :

**Given:** P(n – 1, 3) : P(n, 4) = 1 : 9

**To find:** value of n

We know,

So, according to question:

P(n – 1, 3) : P(n, 4) = 1 : 9

⇒ n = 9

**∴** **The value of n = 9**

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Which of the following are true :

(2 + 3)! = 2! + 3!

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