1/2+5/6+11/12+19/20+29/30 =(1-1/2)+(1-1/6)+(1-1/12)+(1-1/20)+(1-1/30) =[1-(1-1/2)]+[1-(1/2-1/3)]+[1-(1/3-1/4)]+[1-(1/4-1/5)]+[1-(1/5-1/6)] =1-1+1/2+1-1/2+1/3+1-1/3+1/4+1-1/4+1/5+1-1/5+1/6 =4+1/6 =4又1...