1/2+1/6+1/12+...1/9702+1/9900=1/(1x2)+1/(2x3)+1/(3x4)+...+1/(98x99)+1/(99x100)=1-1/2+1/2-1/3+1/3-1/4+...+1/98-1/99+1/99-1/100=1-1/100=99/100
