Answer
$0.84\Omega $
Work Step by Step
We know that $ R_{eq1}=(\frac{1}{4.8\Omega}+\frac{1}{3.3\Omega}+\frac{1}{8.1\Omega})^{-1}=1.575\Omega $
Now $ R_{eq1}$ is in series with $6.3\Omega $
$\implies R_{eq2}=R_{eq1}+6.3\Omega=1.57\Omega+6.3\Omega=7.875\Omega $
The final equivalent resistance can be determined as
$ R_{eq}=[(\frac{1}{1.5\Omega}+\frac{1}{2.5\Omega})+\frac{1}{R_{eq2}}]^{-1}$
$ R_{eq}=[(\frac{1}{1.5\Omega}+\frac{1}{2.5\Omega})+\frac{1}{7.875\Omega}]^{-1}$
$ R_{eq}=0.84\Omega $
