1/2+1/6+1/12+.1/9900
问题描述:
1/2+1/6+1/12+.1/9900
答
答:原式
=1/(1*2)+1/(2*3)+1/(3*4)+...+1/(99*100)
=(1/1-1/2)+(1/2-1/3)+(1/3-1/4)+...+(1/99-1/100)
=1-1/100
=99/100