$\left. \begin{matrix}{{R}_{a}}=\frac{R}{R+r}\Rightarrow 0/9=\frac{R}{R+0/3}\Rightarrow R=2/7  \\{{R}_{a}}=\frac{V}{E}\Rightarrow V=E\times {{R}_{a}}=6\times 0/9=5/4  \\\end{matrix} \right\}\Rightarrow V=RI\Rightarrow I=\frac{5/4}{2/7}=2A$