Suppose a firm issued a 10% coupon 20 years ago with a face value of $1,000. The bond now has 10 years left until its maturity date but the firm is now having financial difficulties. Investors believe that the firm will be able to make good on the remaining interest payments but that at the maturity date, the firm will be forced into bankruptcy, and bondholders will receive only 70% of par value. The bond is selling now at $750.

Calculate the yield to maturity based on the expected payments after the news of the financial difficulties.
Explain and show work!