A firm has three debt issues outstanding with the following characteristics:

Issue A: $450 million market value of bonds with current effective annual ytm of 6.6%

Issue B: $325 million market value of bonds with current effective annual ytm of 5.2%

Issue C: $225 million market value of bonds with current effective annual ytm of 8.7%

What is the weighted average yield to maturity for this firm?

What is the after-tax cost of debt for this firm if their tax rate is 30%?