$\overrightarrow{\mathrm{a}}$ and $\overrightarrow{\mathrm{b}}$ are non zero non-collinear vectors such that $\left|\overrightarrow{\mathrm{a}}\right|=2, \overrightarrow{\mathrm{a}}.\overrightarrow{\mathrm{b}}=1$ and angle between $\overrightarrow{\mathrm{a}}$ and $\overrightarrow{\mathrm{b}}$ is $\frac{\mathrm{\pi }}{3}.$ If $\overrightarrow{\mathrm{r}}$ is any vector satisfying $\overrightarrow{\mathrm{r}}.\overrightarrow{\mathrm{a}}=2, \overrightarrow{\mathrm{r}}.\overrightarrow{\mathrm{b}}=8,\left(\overrightarrow{\mathrm{r}}+2\overrightarrow{\mathrm{a}}-10\overrightarrow{\mathrm{b}}\right).\left(\overrightarrow{\mathrm{a}}\times \overrightarrow{\mathrm{b}}\right)=6$ and is equal to $\overrightarrow{\mathrm{r}}+2\overrightarrow{\mathrm{a}}-10\overrightarrow{\mathrm{b}}=\mathrm{\lambda }\left(\overrightarrow{\mathrm{a}}\times \overrightarrow{\mathrm{b}}\right)$ then $\mathrm{\lambda }=$