$2-$ Given the following information and assuming a stripping cost of $$7\mathrm{.}50$ per tonne and a profit allowance of $$5\mathrm{.}00$ per tonne, calculate the cutoff grade for a copper price of $$3\mathrm{.}50//$lb$.$ Show your calculations. $(6$ points$)$

Heads $\%$ Cu $2\mathrm{.}602\mathrm{.}302\mathrm{.}101\mathrm{.}801\mathrm{.}501\mathrm{.}20\%$ Rec'd $98\mathrm{.}0096\mathrm{.}0093\mathrm{.}0090\mathrm{.}0088\mathrm{.}0080\mathrm{.}00$ Costs $($$$/$tonne$)$ Mining $18\mathrm{.}7518\mathrm{.}7518\mathrm{.}7518\mathrm{.}7518\mathrm{.}7518\mathrm{.}75$ Milling $23\mathrm{.}4024\mathrm{.}1025\mathrm{.}7529\mathrm{.}0031\mathrm{.}0533\mathrm{.}00$ Others $($O$/$H$,$ Depr, Refining, etc.$)13\mathrm{.}2513\mathrm{.}2513\mathrm{.}2513\mathrm{.}2513\mathrm{.}2513\mathrm{.}25$