1/2+1/6+1/12+1/30+1/42+1/56=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/5-1/6)+(1/6-1/7)+(1/7-1/8)=(1-1/4)+(1/5-1/8)=3/4+3/40=33/40楼主你中间好像漏写了一个1/20.如果是那样,则1/2+1/6+1/12+1/20+1/30+1/42+1/56=(1-1/2)...