If `^n P_r=^n P_(r+1)a n d^n C_r=^n C_(r-1,)` then the value of `n+r` is.

If ^n C_r=84 ,^n C_(r-1)=36 ,a n d^n C_(r+1)=126 , then find the value of ndot

If ""^(n)P_r = ""^(n)P_(r-1) and ""^(n)C_(r) = ""^(n)C_(r-1) , find the values of n and r.

If ""^(nP_(r)=""^(n)P_(r+1) and ""^(n)C_(r)=""^(n)C_(r-1) find n and r.

If ""^(n)P_(r)=3024 & ""^(n)C_(r)=126 then the value of r =

If ^n+1C_(r+1) : ^n C_r : ^(n-1)C_(r-1)=11 :6:3, then n r =

If ""^(n)P_r = 360 , ""^(n)C_r = 15 then find the value of n =…………………….

Find the sum sum_(r=1)^n r^2(^n C_r)/(^n C_(r-1)) .

If a_(n) = sum_(r=0)^(n) (1)/(""^(n)C_(r)) , then the value of (sumsum)_(0leiltjlen) (i/(""^(n)C_(i))+j/(""^(n)C_(j)))

If ""^(n)P_(r)=110 , then n + r =

If (4x^(2) + 1)^(n) = sum_(r=0)^(n)a_(r)(1+x^(2))^(n-r)x^(2r) , then the value of