सिध्द कीजिए कि -
`(C_(r) + C_(r-1))/(C_(r-1)) = (n+1)/(r)`

Prove that .^(n)C_(r)+^(n)C_(r-1)=^(n+1)C_(r)

""^(n)C_(r+1)+^(n)C_(r-1)+2.""^(n)C_(r)=

Prove that : (""^(n)C_(r+1))/(""^(n)C_(r))=(n-r)/(r+1)

If .^(n)C_(r-1)=.^(n)C_(3r) , find r.

If f(x)=sum_(r=1)^(n) { r^(2) (""^(n)C_(r)- ^(n) C_(r-1))+ (2r+1) ^(n) C_(r)} and f(30)=30(2)^(lambda), then the value of lambda is

Property: ( i )nC_(r)=nC_(n-r)( ii) n(C_(r))/(r+1)=(n+1)(C_(r+1))/(n+-1)