Addition & Subtraction of Vectors question from JEE Main 2021 (25 Jul, Shift 1)

Answer: (b)

1. Triangle law: when two vectors are drawn head to tail, the vector from the free tail to the free head is their sum.
2. Rewrite each relation: (a) $\vec{C} = \vec{A} + \vec{B}$; (b) $\vec{A} = \vec{B} + \vec{C}$; (c) $\vec{B} = \vec{A} + \vec{C}$; (d) $\vec{A} + \vec{B} + \vec{C} = 0$ (closed head-to-tail loop).
3. Match each with the figure in which the single vector on the left runs from the start of the other two to their end; (d) is the figure where all three arrows go round the triangle in one sense.
4. This gives (a) → (iv), (b) → (iii), (c) → (i), (d) → (ii).
5. So the answer is (b).