Williamson, Inc., has a debt$-$equity ratio of $2\mathrm{.}59.$ The company's weighted average cost of capital is $10$ percent, and its pretax cost of debt is $6$ percent. The corporate tax rate is $24$ percent.

a$.$ What is the company's cost of equity capital? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

b$.$ What is the company's unlevered cost of equity capital? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

c$.$ What would the weighted average cost of capital be if the company's debt$-$equity ratio were $\mathrm{.}75$ and $1\mathrm{.}70?($Do not round intermediate calculations and enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$