1/2+5/6+11/12+19/20+29/30+41/42+...+9899/9900=1-1/2+1-1/6+1-1/12+1-1/20+1-1/30+...+1-1/9900=99-(1/2+1/6+1/12+...+1/9900)=99-(1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+...+1/99-1/100)=99-(1-1/100)=98又1/10...