If `sum_(r=0)^nr/(^n C_r)=sum_(r=0)^n(n^2-3n+3)/(2.^n C_r)` , then `n=1` b. `n=2` c. `n=3` d. none of these

If sum_(r=0)^(n)(2r)/(C(n,r))=sum_(r=0)^(n)(n^(3)-3n+3)/(C)(n,r)

If sum_(r=0)^n(2r+3)/(r+1), C_r=((n+k)*2^(n+1)-1)/(n+1) then 'k' is

If a_(n)=sum_(r=0)^(n)(1)/(*^(n)C_(r)), the value of sum_(r=0)^(n)(n-2r)/(n^(n)C_(r))

Prove that sum_(r=0)^(s)sum_(s=1)^(n)C_(s)^(n)C_(r)=3^(n)-1

sum_(r=0)^n((-1)^r*C_r)/((r+1)(r+2)(r+3))=1/(a(n+b)), then a+b is

If s_(n)=sum_(r=0)^(n)(1)/(.^(n)C_(r))and t_(n)=sum_(r=0)^(n)(r)/(.^(n)C_(r)) , then (t_(n))/(s_(n)) is equal to