Hi, im having some troubles with this question, so i really hope that someone can help me with this:

Restex maintains a debt-equity ratio of 0.85, and has an equity cost of capital of 12% and a debt cost of capital of 7%. Restex’s corporate tax rate is 40%, and its market capitalization is $220 million.

a. If Restex’s free cash flow is expected to be $10 million in one year, what constant expected future growth rate is consistent with the firm’s current market value?

b. Estimate the value of Restex’s interest tax shield.

Im only having problems with the question b. I got in a) that because the enterprise value is 407 then g=.059. But my problem with b) is that at the moment to calculate the present value of the tax shield following the formula of τ*D (i got that D=220*.65=187) and im getting τ*D=.4*187=74.8 .

But following the other formula that says that the present value of the tax shield is the difference between the levarage and the unlaverage market value: VL = VU + tcD.

First i got that VU=267 (calculating the pretax wacc first). So the present value of the tax shield is 140.