MCQ
The largest coefficient in the expansion of $(1 + x)10$ is:
  • $\frac{10!}{(5!)^2}$
  • B
    $\frac{10!}{5!}$
  • C
    $\frac{10!}{(5!\times4!)^2}$
  • D
    $\frac{10!}{(5!\times4!)}$

Answer

Correct option: A.
$\frac{10!}{(5!)^2}$
Given: $(1 + x)10$
The greatest coefficient will always occur in the middle term.
Hence, the total number of terms in an expansion is $11. ($ i.e. $10 + 1 = 11)$
Therefore, middle term $ =\Big[\big(\frac{10}{2}\big)+1\Big]=5+1=6\text{th }\text{term}.$
So, $T6 ={^{10}C_5} \times x^5$
Therefore, the coefficient of the greatest term $={^{10}C_5}$$=\frac{10!}{(5!)^2}.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free