Suppose, you are evaluating a firm$$s capital structure policy. The firm has a zero debt policy currently. Running the CAPM model yielded a return of $15\%.$ This firm has decided to borrow so that the debt$-$to$-$equity ratio is $1$:$2\mathrm{.}5.$ Cost of debt is $10\%.$ Tax rate is $25\%.$ Estimate the firm$$s weighted average cost of capital after the restructure.