Given r>1,n>2, the coefficients of the (3r)th and (r+2)th terms in (1+x)²ⁿ are equal. Then (a) n=2r (b) n=2r+1 (c) n=3r (d) none of these

Correct answer: (a) n=2r 2n 3r-1 = 2n r+1 →(3r-1)+(r+1)=2n→ n=2r. JEE Advanced 1983 · Binomial Theorem — verified solution by the Vidaara Team.

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[JEE Advanced 1983] given r 1 n 2 the coefficients of the 3r th and r 2

VAVidaara Admin Asked 2d ago 0 views 1 answer

Given $r>1,n>2$, the coefficients of the $(3r)$th and $(r+2)$th terms in $(1+x)^{2n}$ are equal. Then

(a) $n=2r$
(b) $n=2r+1$
(c) $n=3r$
(d) none of these

VAVidaara Admin ✓ Vidaara Team ✓ Accepted · 2d ago ▲ 0

Correct answer: (a) $n=2r$

$\binom{2n}{3r-1}=\binom{2n}{r+1}\Rightarrow(3r-1)+(r+1)=2n\Rightarrow n=2r$.

JEE Advanced 1983 · Binomial Theorem — verified solution by the Vidaara Team.

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