Let $\overrightarrow{a}, \overrightarrow{b}$ and $\overrightarrow{c}$ be three non-zero non-coplanar vectors and $\overrightarrow{p}, \overrightarrow{q}$ and $\overrightarrow{r}$ be three vectors defined as $\overrightarrow{p}=\overrightarrow{a}+\overrightarrow{b}-2\overrightarrow{c}; \overrightarrow{q}=3\overrightarrow{a}-2\overrightarrow{b}+\overrightarrow{c} \mathrm{and} \overrightarrow{\mathrm{r}}=\overrightarrow{\mathrm{a}}-4\overrightarrow{\mathrm{b}}+2\overrightarrow{\mathrm{c}}$

If the volume of parallelepiped determined by $\overrightarrow{a}, \overrightarrow{b} \mathrm{and} \overrightarrow{c}$ is $V_1$ and that of the parallelepiped determined by $\overrightarrow{p}, \overrightarrow{q} \mathrm{and} \overrightarrow{r}$ is $V_2$ then, $V_2={\mathrm{\text{KV}}}_1$ implies that the value of $K$ is