$1.$Amazon has both debt and equity in its capital structure. The ratio between debt and equity is $40$:$60.$ Amazon's common stock has a beta, b$,$ of $1\mathrm{.}4.$ The risk$-$free rate is $6\%,$ and the expected market return is $10\%.$ After tax cost of debt is $8\%.$ Tax rate is $20\%.$a$)$Identify the market risk premium on Amazon common stock.b$)$Identify Amazon stock's required return using the Capital Asset Pricing Model.c$)$Identify weighted average cost of capital of Amazon.

$2.$ A firm has issued $10$ percent preferred stock, which sold for AED $77\mathrm{.}5$ per share par value The cost of issuing and selling the stock was AED $2\mathrm{.}5$ per share. The firms marginal tax rati is $20$ percent. Calculate cost of preferred stocks. Also analyze the cost of the preferred stoc if cost of issuing and selling stock increases to AED $5$ per share and par value is AED $75$ p share.Discover which scenario will be better for the company and why? Also, show working.