The magnitude of the vector $$6 \hat{i}-2 \hat{j}+3 \hat{k}$$ is :

If a line makes angles of $$90^{\circ}, 135^{\circ}$$ and $$45^{\circ}$$ with the $$x, y$$ and $$z$$ axes respectively, then its direction cosines are:

The angle between the lines $$2 x=3 y=-z$$ and $$6 x=-y=-4 z$$ is:

If for any two events $$\mathrm{A}$$ and $$\mathrm{B}, P(A)=\frac{4}{5}$$ and $$P(A \cap B)=\frac{7}{10}$$, then $$P(B / A)$$ is equals to: