Download the app

Questions  

If  nC4,nC5 and  nC6 are in A.P., then a value of n can be 

Remember concepts with our Masterclasses.

80k Users
60 mins Expert Faculty Ask Questions
a
6
b
7
c
8
d
9

Ready to Test Your Skills?

Check Your Performance Today with our Free Mock Tests used by Toppers!

detailed solution

Correct option is B

As  nC4,nC5 and nC6 are in A.P.2 nC5=nC4+nC6⇒ 2= nC4 nC5+ nC6 nC5=n!4!(n−4)!5!(n−5)!n!+n!6!(n−6)!5!(n−5)!n!⇒ 2=5n−4+n−56⇒n2−21n+98=0⇒ n=7,14.


Similar Questions

 nCr+2nCr1+nCr2 is equal to


whats app icon
phone icon