In the given network of four resistors, the equivalent resistance is,

A conductor with a rectangular cross-section has dimensions $\left(4a\times 2a\times a\right)$ as shown in the figure. Resistance across $AB$ is $x$, across $CD$ is $y$, and across $EF$ is $z.$ Then, 

In the circuit shown, the equivalent resistance between points $A$ and $B$ is,

Find the equivalent resistance between the terminals $X$ and $Y$.