问题如下：
Today is 5 June 2013. A three-year semi-annual bond with a coupon rate of 6% just paid its first coupon payment. The interest payment dates are 5 April and 5 October. The yield-to-maturity equals to 5%. If day count convention is 30/360, calculate the flat price of this bond on 5 June 2013.
选项：
A.102.17
B.100.00
C.100.24
解释：
A is correct.
The bond price at the first coupon payment date:
N=5，I/Y=2.5，PMT=3，FV=100 → PV= -102.32
The number of days between 5 April 2013 (first coupon payment date) and today (5 June 2013) is 60 days based on the 30/360 day count convention.
Full price today:
102.32×（1+2.5%）60/180=103.17
Accrued Interest =100 × 3% × (60/180)=1
Flat price today:
Flat price= Full price- Accrued Interest=103.17-1=102.17
这里计算器算出来的后面 5 期的PV ，是折现到了4/5号的 PV，为啥不用把 4/5 自己的 3 块现金流也一起加进去来算 full price 呢？
