(a) Find the equations of the diagonals of the parallelogram PQRS whose vertices are $P(4,2,-6), Q(5,-3,1), R(12,4,5)$ and $S(11,9,-2)$. Use these equations to find the point of intersection of diagonals. OR(b) A line $l$ passes through point $(-1,3,-2)$ and is perpendicular to both the lines $\; \frac{x}{1} = \; \frac{y}{2} = \; \frac{z}{3}$ and $\; \frac{x+2}{-3} = \; \frac{y-1}{2} = \; \frac{z+1}{5}$. Find the vector equation of the line $l$. Hence, obtain its distance from origin.