Question

计算：1*2分之1+2*3分之1+3*4分之1+.+49*50分之1

Answer 1

1/(1*2)+1/(2*3)+...+1/(49*50)

=(1-1/2)+(1/2-1/3)+(1/3-1/4)+...+(1/49-1/50)

=1-1/2+1/2-1/3+1/3-1/4+...+1/49-1/50

=1-1/50

=0.98