Tywin borrowed $$8500$ from the Iron Bank at $6\mathrm{.}2\%$ interest. He agreed to repay the loan in a single payment at the end of the term in $1\mathrm{.}5$ years,

Tywin borrowed $$8500$ from the Iron Bank at $6\mathrm{.}2\%$ interest. He agreed to repay the loan in a single payment at the end of the term in $1\mathrm{.}5$ years.

a$.$ Determine the loan payment amount if the interest is simple interest. $(2$ marks$)$

b$.$ How much would Tywin have to pay back if the interest is compounded semi$-$annually? $(2$ marks$)$

c$.$ For part $($b$),$ how much of this amount paid back would be interest? $(1$ mark$)$