Question

1/1x2 +1/2x3 +1/3x4+…+1/99x100

Answer 1

=1-1/2+1/2-1/3+...+1/99-1/100

=1-1/100=99/100

Answer 2

= 1/1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + ... + 1/99 - 1/100

= 1 - 1/100

= 99/100

Answer 3

= 99/100