Answer:
5.75%
Explanation:
to determine the effective cost of the debt, we can use an excel spreadsheet and the IRR function:
effective interest rate = 8.71%
we can also calculate the answer using the annuity and present value formula:
1,016 = [90 x ({1 - [1 / (1 + i)⁸]} / i)] + [1,000 / (1 + i)⁸]
but it's much more complicated and the result is the same.
since the effective interest rate = 8.71%, then the after tax rate = 8.71% x (1 - 34%) = 8.71% x 0.66 = 5.7486% ≈ 5.75%