$1.$ FaceChat LTD has a D$/$E $=1\mathrm{.}5.$ Its WACC $=8\mathrm{.}4\%$ and cost of debt is $5\mathrm{.}9\%.$ The corporate tax rate $=35\%.(25$ pts$)$

a$.$ What is the cost of equity capital?

b What is the unlevered cost of equity capital?

c$.$ What would the cost of equity be if the D$/$E $=2\mathrm{.}0$; D$/$E $=1\mathrm{.}0$; D$/$E $=0?$