Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa

If { }^{2 n} C_{3}:{ }^{n} C_{3}: 10: 1,then the ratio \left(n^{2}+3 n\right):\left(n^{2}-3 n+4\right) is :

Option: 1

27 :11


Option: 2

35 : 16


Option: 3

2 : 1


Option: 4

65 : 37


Answers (1)

best_answer

\frac{{ }^{2 n} C_{3}}{{ }^{\mathrm{n}} C_{3}}=10 \Rightarrow \frac{2 \mathrm{n} !(\mathrm{n}-3) !}{(2 \mathrm{n}-3) ! \mathrm{n} !}=10
\frac{2 \mathrm{n}(2 \mathrm{n}-1)(2 n-2)}{\mathrm{n}(\mathrm{n}-1)(\mathrm{n}-2)}=10
\frac{4(2 \mathrm{n}-1)}{\mathrm{n}-2}=10 \Rightarrow 8 \mathrm{n}-4=10 \mathrm{n}-20
2 \mathrm{n}=16

Now  \mathrm{\frac{n^{2}+3 n}{n^{2}-3 n+4}}
=\frac{64+24}{64-24+4}=\frac{88}{44}=2
Ans. 3

Posted by

rishi.raj

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

JEE Main 2027: NTA allows fresh application forms, warns against multiple IDs; correction window from Nov 27
anam-khan

JEE Main 2027: NTA advises Aadhaar re-KYC on DigiLocker before registration, issues guidelines
anam-khan

Kota: JEE aspirant dies by suicide in PG room; another student's death triggers allegations of negligence

Latest Question