(a) If $\vec{a}$ and $\vec{b}$ are position vectors of point A and point B respectively, find the position vector of point C on BA produced such that $\text{BC} = 3\text{BA}$. OR (b) Vector $\vec{r}$ is inclined at equal angles to the three axes x, y and z. If magnitude of $\vec{r}$ is $5\sqrt{3}$ units, then find $\vec{r}$.

Year	Paper Code	Set	Position
CBSE 2025	Series 65-6	Set 1	Question 24
CBSE 2025	Series 65-6	Set 2	Question 22
CBSE 2025	Series 65-6	Set 3	Question 21

• Step 1: Stating the fundamental formula / law statement (+1 Mark)
• Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
• Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)