Please show all work for every part, thank you. $(14\%$;$2\%$ for each subquestion$)$ A firm has non$-$dividend$-$paying equity $($Et: equity value at time t$)$ and

zero$-$coupon debt $($Bt: debt value at time $t$; promised payment at time $T$ is $250).A_t$ is the asset value of the

firm at time t$.A_0=280,r_c=2\%($continuous time$),$ asset volatility $=20\%,T=5$ years.

$($a$)$ What is the current market value of equity?

$($b$)$ What is the current market value of risky debt?

$($c$)$ Calculate the quasi debt$-$to$-$asset ratio $d=(B\frac{e^{-TT}}{A_0}).$

$($d$)$ Calculate credit spread $(Y-r)=(-\frac{1}{T})**ln[N(d_2)+(\frac{1}{d})**(N)(-d_1)].$

$($e$)$ If the promised payment at time $T$ changes from $250$ to $300,$ calculate the percent change $(\%)$ of the

quasi debt$-$to$-$asset ratio $d.$

$($f$)$ If the promised payment at time $T$ changes from $250$ to $300,$ calculate the new credit spread $(\%)$ and

the percent change $(\%)$ of the credit spread.

$($g$)$ If the promised payment at time $T$ changes from $250$ to $300,$ calculate the new equity value and the

percent change $(\%)$ of the equity value.