Hello I need the following questions answered with explanations. Questions involving things such as WACC need to have the steps written out if possible. Thank you

Suppose you have a firm with the following information (ignore financial distress costs):

Total Firm value (with $5 million in Debt) = $15 million

r₀ = 10%

Tax Rate = 35%

r_B = 7%

a.What is the Company's required rate of return on Equity?

b.What is the Company's WACC?

c.Estimate the value of this firm as an unlevered entity.

Now suppose this firm had only $3 million in debt to start off with.

d.What would have been the required rate of return for equity?

e.What would have been the WACC?