问题如下：
A zero-coupon bond matures in 15 years. At a market discount rate of 4.5% per year and assuming annual compounding, the price of the bond per 100 of par value is closest to:
选项：
A.51.30.
B.51.67.
C.71.62.
解释：
B is correct.
The price of the zero-coupon bond is closest to 51.67. The price is determined in the following manner:
where:
PV = present value, or the price of the bond
r = market discount rate, or required rate of return per period
N = number of evenly spaced periods to maturity
PV = 51.67
如果用计算器的话，把 PMT 设置成 0，也能求出来对应的 PV=-51.67
想问下这个题对应的公式在强化串的讲义里我好像没有找到
还是说通过这个公式：
因为 zero coupon，所以 CPN 前面 14 项都是 0 了，只有最后一项了
