Sequence And Series Question 118

Question: The sum to $ n $ terms of the series $ 2^{2}+4^{2}+6^{2}+……….. $ is

[MP PET 1994]

Options:

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

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

C) $ \frac{n(n+1)(2n+1)}{6} $

D) $ \frac{n(n+1)(2n+1)}{9} $

Show Answer

Answer:

Correct Answer: B

Solution:

$ 2^{2}+4^{2}+6^{2}+……..+{{(2n)}^{2}} $ $ =2^{2}(1^{2}+2^{2}+3^{2}+…….+n^{2}) $ $ =\frac{4n(n+1)(2n+1)}{6}=\frac{2n(n+1)(2n+1)}{3} $ .