Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • The coefficient in the third term of the expansion of <img alt="\left(

The coefficient in the third term of the expansion of \left(x^2+\frac{1}{4}\right)^n when expanded in decreasing powers of x is 31, then n is equal to

 

Option: 1

16


Option: 2

20


Option: 3

30


Option: 4

32


Answers (1)

best_answer

The coefficient of third term will be nC2\left(\frac{1}{4}\right)^2=31 \Rightarrow\frac{n(n-1)}{2 \times 16}=31

⇒ n(n –1) = 32 . 31 ⇒ n = 32.

Hence (D) is the correct answer.

 

Posted by

chirag

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

Amrita BTech Admission 2025: JEE Main-based registration deadline extended to August 30
anam-khan

DASA, CSAB Special round 2 seat allotment result 2025 declared on csab.nic.in

Latest Question