JEE Mains Model Paper 13

1) Incorrect, because a + b + c + d can be zero in many ways other than a, b, c and d musteach be a null vector e.g., if the vectors are in different directions, then their resultant willbe zero.
2) Correct, since a + b + c + d = 0, a + c = -(b + d)
3) Correct, since a + b + c + d = 0, a = -(b + c + d).
4) Correct, since a + b + c + d = 0, a + (b + c) + d = 0