" Sum of series "(1+2)+(3+5)+(6+7)+(9+10)+......+(93+94)+(95+97)+(98+99)" will be "

Sumn of nseries (1+2)+(3+5)+(6+7)+(9+10)+..........+(93+94)+(95=97)+(98+99) will be :

Sum of the series 1/(1*2*3)+5/(3*4*5)+9/(5*6*7 )+... is equal to

The sum of the series (1)/(1.3.5)+(1)/(3.5.7)+(1)/(5.7.9)+... is

The sum of the series 5/(1. 2.3)+7/(3. 4.5)+9/(5. 6.7)+ ....is equal to

The sum of the series (5)/(1.2.3)+(7)/(3.4.5)+(9)/(5.6.7)+.... is equal to

The unit digit of the following expression (1 !)^(99) + (2!)^(98) + (3!)^(97) + (4!)^(96) + …..(99 !)^1 is :