Questions $11-13$ are based on the following information

The firm's combined marginal state, local, and federal tax rate was $40\%.$ The $10-$year Treasury bond rate is $5\%$ and the borrowing rate for companies exhibiting levels of creditworthiness similar to No Growth is $7\%.$ The historical risk premium for stocks over the risk free rate of return is $5\mathrm{.}5\%.$ The firm's beta was estimated to be $1\mathrm{.}0.$ The firm's debt to equity ratio is $50\%.$

$11$ What is the after$-$tax cost of debt of this firm?

a $2\mathrm{.}8\%$

b $3\%$

c $4\mathrm{.}2\%$

d $5\%$

e $7\%$

$12$ What is the cost of equity of this firm?

a $5\mathrm{.}5\%$

b $7\%$

c $10\mathrm{.}5\%$

d $12\%$

e $13\mathrm{.}5\%$

$13$ What is the weighted average cost of capital $($WACC$)$ of this firm?

a $5\mathrm{.}65\%$

b $7\mathrm{.}35\%$

c $8\mathrm{.}40\%$

d $10\mathrm{.}5\%$

e $11\mathrm{.}8\%$