Question

∴ its equivalent $R^{'} = \frac{4 \times 8}{12} = \frac{8}{3}\Omega$

Circuit can be redrawn as

$$\begin{matrix} & R_{eq} = \frac{8}{3} + \frac{1}{3} + 1.5 + 5.5 \\ & \ = 10\Omega \\ & i = \frac{V}{R_{eq}} = \frac{5}{10} = 0.5\text{ }A \end{matrix}$$