$($k$)$ In economic view to select the materials using for manufacture the handle cover. The material cost of the plastic material A and the plastic material B is $$5$ per kgs and $$2$ per kgs$.$ The handle cover being fabricated weighs $4$ g $.$ Assume the machinery costs are the same for each material and that operator labour costs are $$\frac{8}{h}r.$

$\backslash$table$[[,$PVC$,$Silicone$],[\backslash$table$[[$Fabrication yield rate$],[($Fully use for making a part$)]],80\%,90\%$