A(n) is a person with specific training or skills in tracking costs and the accomplishment of specific objectives in an electronic commerce initiative.

it may be wrong but i think its a

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.