Question

（1x2分之1）+（2x3分之1）+（3x4分之1）······（99x100分之1）等于多少?

Answer 1

*:乘号

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