If `p+q=1,` then show that `sum_(r=0)^n r^2^n C_rp^r q^(n-r)=n p q+n^2p^2dot`

If p+q=1 then show that sum_(r=0)^(n)r^(2)C_(r)p^(r)q^(n-r)=npq+n^(2)p^(2)

If p+q=1, then value of sum_(r=0)^(n)r^(2)C(n,r)p^(r)q^(n-r) is (1)npq(2)np(1+q) (3) n^(2)p^(2)+npq(4)np^(2)+npq

If ""(n)C_(0), ""(n)C_(1), ""(n)C_(2), ...., ""(n)C_(n), denote the binomial coefficients in the expansion of (1 + x)^(n) and p + q =1 sum_(r=0)^(n) r^(2 " "^n)C_(r) p^(r) q^(n-r) = .

If ""^(n)C_(0), ""^(n)C_(1),..., ""^(n)C_(n) denote the binomial coefficients in the expansion of (1 + x)^(n) and p + q = 1 , then sum_(r=0)^(n) ""r.^(n)C_(r) p^(r) q^(n-r) =

Let S_k=1+q+q^2+...+q^k and T_k=1+(q+1)/2+((q+1)/2)^2+...+((q+1)/2)^k q!=1 then prove that sum_(r=1)^(n+1) ^(n+1)C_rS_(r-1)=2^ nT_n

What is the value of sum_(r=1)^(n) (P(n, r))/(r!) ?

If show that "^(n-1)P_r = (n-r).^(n-1)P_(r-1)

Prove that ""^(n)P_(r )= ""^(n)C_(r )*^rP_(r ) .