If the volume of a parallelopiped, whose coterminus edges are given by the vectors a = i + j + n k, b =2 i +4 j - n k and c = i + n j +3 k ( n ≥ 0),…

If the volume of a parallelopiped, whose coterminus edges are given by the vectors $\displaystyle \overrightarrow{\mathrm{a}}=\hat{i}+\hat{j}+\mathrm{n} \hat{k}, \overrightarrow{\mathrm{~b}}=2 \hat{i}+4 \hat{j}-\mathrm{n} \hat{k}$ and $\displaystyle \overrightarrow{\mathrm{c}}=\hat{i}+\mathrm{n} \hat{j}+3 \hat{k}(\mathrm{n} \geqslant 0)$, is $\displaystyle 158$ cu.units, then :