GRANDI'S SERIES : 1-1+1-1+1-1+1-1+1-1+.....= ?

The sum of the series : 1 + (1)/(1 + 2) + (1)/(1 + 2 + 3)+ .... up to 10 terms, is

If p is positive, then the sum to infinity of the series, 1/(1+p) -(1-p)/(1+p)^2 + (1-p)^2/ (1+p)^3 -........ is

Find the sum of the series e^(x-(1)/(2)(x -1)^(2) + (1)/(3) (x -1)^(3) - (1)/(4) (x -1)^(4) + ...

The sum of the series 1+ (1)/(4) + (1)/(16) + (1)/(64) + ...........oo is