Bond X, with credit rating of AAA and market price of $1050, has a face value of $1,000 and matures in 10 years. The bond makes no payments for the first six years, then pays $180 every six months over the subsequent two years, and finally pays $160 every six months over the last two years. Bond Y, with credit rating of AA and market price of $900, has a face value of $1,000 and a maturity of 10 years; it makes no coupon payments over the life of the bond. Bond Z, with credit rating of A and market price of $800, has a yield to maturity of 3%. What is the yield to maturity of Bond X? Of bond Y? Which of the above bond seems to be overpriced?