题出错了吧……1/2+5/6+11/12+19/20+29/30+......+9701/9702+9899/9900=(1-1/1*1/2)+(1-1/2*1/3)+(1-1/3*1/4)+(1-1/4*1/5)+...+(1-1/98*1/99)+(1-1/99*1/100)=99-(1-1/2+1/2-1/3+1/3-1/4+...+1/98-1/99+1/99-1/100)=99-(1-1/100)=99-99/100=891/100