Bonus problem $(10$ pts$)$:

Assuming a liner system consists of a geomembrane $($with a thickness of $0\mathrm{.}3$ cm $)$ over $0\mathrm{.}5$ m of clay. The membrane and the clay have a saturated hydraulic conductivity $(K_s)$ of $1{10}^{-12}$ and $1{10}^{-7}c\frac{m}{sec},$ respectively.

$(1)$ Please calculate the equivalent hydraulic conductivity $(K_{eq})$ of this liner system.