1. The problem statement, all variables and given/known data Resultant of which of a following may be equal to zero? 1)10 N, 10 N , 10N 2) 10 N, 10 N , 25 N 3) 10 N, 10 N , 35N 4)None of these More than one option can be correct. 2. Relevant equations Addition of vectors 3. The attempt at a solution 1) Resultant of these three forces can equal to zero if two of the forces make 120 degrees angle with each other and their resultant is opposite in direction with the third force. Answer at the back of textbook says option 1 is correct. I don't know how can we be so sure that other two options are wrong?