The value of m for which the points with position vectors - i - j +2 k, 2 i + m j +5 k and 3 i +11 j +6 k are collinear, is

The value of $\displaystyle \mathrm{m}$ for which the points with position vectors $\displaystyle -\hat{\mathrm{i}}-\hat{\mathrm{j}}+2 \hat{\mathrm{k}}$, $\displaystyle 2 \hat{\mathrm{i}}+\mathrm{m} \hat{\mathrm{j}}+5 \hat{\mathrm{k}}$ and $\displaystyle 3 \hat{\mathrm{i}}+11 \hat{\mathrm{j}}+6 \hat{\mathrm{k}}$ are collinear, is