Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  CBSE XI  >>  Math  >>  Binomial Theorem
0 votes

If the sum of coefficients in the expansion of $(a+b)^n$ is $4096$ then the greatest coefficient in the expansion is

$\begin{array}{1 1}(A)\;1594\\(B)\;792\\(C)\;924\\(D)\;2924\end{array} $

Can you answer this question?

1 Answer

0 votes
Sum of coefficients =4096
$\therefore (a+b)^n$ when a,b are each 1=4096
$\Rightarrow (1+1)^n=4096=2^{12}$
$\Rightarrow n=12$
Hence n is even
$\Rightarrow$ Greatest coefficient
$\Rightarrow nC_{n/2}=12C_6$
$\Rightarrow \large\frac{12!}{6!6!}$
$\Rightarrow 924$
Hence (C) is the correct answer.
answered Jun 26, 2014 by sreemathi.v
Why 'a' and 'b' should reach '1' in order to determine 'n'?

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App