Please show me step by step NOT in Excel. Thank you in advance!

Simple Bond Valuation Example . Several years ago Pies in the Skies Ltd issued $100 bonds at par value with a yield to maturity of 8 per cent. Now, with 8 years left to maturity on the bonds, the company is experiencing difficulties to the extent that the yield to maturity on the bonds has increased to 12 per cent. . Calculate the price of the bond following the increase in the yield to 12%. Explain what has happened to the price since issue of the bond. Investors believe that Pies in the Skies Ltd can pay the promised coupon payments, but that the company will go bankrupt when the bond matures, and the principal repayments become due. Investors expect that they will only receive 80 percent of the face value at maturity. If an investor were to purchase the bond today, calculate the price the investor is willing to pay for this bond