[" 3.Evaluate the following: "],[[" (i) "sum_(n=1)^(11)(2+3^(n))," (ii) "sum_(k=1)^(n)(2^(k)+3^(k-1))]]

Evaluate : sum_(k=1)^n (2^k+3^(k-1))

Evaluate : sum_(k=1)^n (2^k+3^(k-1))

sum_(k=1)^n k^3=

Find sum_(k=1)^(n)(1)/(k(k+1)) .

Evaluate : (i) sum_(n=1)^(10)(2+3^(n))" " (ii) sum_(k=1)^(n)[2^(k)+3^((k-1))]" " (iii) sum_(n=1)^(8) 5^(n)

sum_(k =1)^(n) k(1 + 1/n)^(k -1) =

Let f(n)=(sum_(r=1)^(n)((1)/(r)))/(sum_(k=1)^(n)(k)/(2n-2k+1)(2n-k+1))