Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa

What is the 5th term in the expansion of \left ( 3a+b \right )^9?

Option: 1

^9C_5 .3^4.a^{4}.b^5


Option: 2

^9C_4 .3^5.a^{5}.b^4


Option: 3

^9C_4.a^{5}.b^4


Option: 4

None of these


Answers (1)

best_answer

General term in this expansion is

 T_{r+1}=^nC_r.(3a)^{n-r}(b)^r

For fifth term we put r = 4

Thus T_{5}=^9C_4 .(3a)^{9-4}(b)^4= ^9C_4 .3^5.a^{5}.b^4

 

Posted by

Ritika Jonwal

View full answer

JEE Main high-scoring chapters and topics

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

Similar Questions

Latest Question