This bond pays 20 coupons of $12,000 (12% or $24,000 for each year)
PLUS the bond redemption itself at the end of period 20. We'll set
this up as a net present value (NPV) problem, with a discount of 5.0%
each six months (10% per year). The NPV is the price of the bond.
I've placed the NPV calculations in a spreadsheet here:
The total value of the bond coupons is $149,546.52, while the value of
getting the principal back in 10 years is $75,377.90. So, the market
value of the bond is $224,924.42.
You'll note that the price is higher than the bond. This is because
the coupon rate is above the market interest rate of 10%. Normally a
corporate finance staff would try to price the bond closer to par
value, but this shows how interest rate spreads work to RAISE the
price of a bond.