Question

2乘3分之1家3乘4分之1加4乘5分之1加……加99乘100分之1等于?

Answer 1

1/2×3+1/3×4+……+1/99×100
=1/2-1/3+1/3-1/4+……+1/99-1/100
=1/2-1/100
=49/100