If number of terms in the expansion of ( x − 2 y + 3 z ) n are 45, then n = Options: A . &nbsp 7 B . &nbsp 8 C . &nbsp 9 D . &nbsp None of these

Answer: Option B : B ( n + 1 ) ( n + 2 ) 2 = 45 or n 2 + 3n - 88 = 0 ⇒ n = 8 .

If number of terms in the expansion of (x−2y+3z)n are 45, then n =

Question -

If number of terms in the expansion of $(x - 2 y + 3 z)^{n}$ are 45, then n =

Options:

A . 7

B . 8

C . 9

D . None of these

Answer: Option B
:
B

$\frac{(n + 1) (n + 2)}{2}$ = 45 or $n^{2}$ + 3n - 88 = 0 $\Rightarrow$ n = 8 .

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