Binomial Theorem And Its Simple Applications Question 183

Question: $ n^{n}{{( \frac{n+1}{2} )}^{2n}} $ is

[AMU 2001]

Options:

A) Less than $ {{( \frac{n+1}{2} )}^{3}} $

B) Greater than $ {{( \frac{n+1}{2} )}^{3}} $

C) Less than $ {{(n!)}^{3}} $

D) Greater than $ {{(n!)}^{3}}, $

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Answer:

Correct Answer: D

Solution:

  • $ y=n^{n}{{( \frac{n+1}{2} )}^{2n}} $

Put n = 2, $ y=2^{2}{{( \frac{3}{2} )}^{4}}=4,.,\frac{81}{8\times 2}=\frac{81}{4}\tilde{-} $ 20

Option (a) $ ={{( \frac{n+1}{2} )}^{3}}=\frac{27}{8}<y $

Option (b) $ ={{( \frac{n+1}{2} )}^{3}}=\frac{27}{8}<y $

Option (c) $ ={{(2!)}^{3}}=8<y $

Option (d) $ ={{(2!)}^{3}}=8<y $ .