hpr是线上？？为什么other measurements 是线下方法？这两类方法有什么适用情形吗？

An investor will receive an annuity of $4,000 a year for ten years. The first payment is to be received five years from today. At a 9% discount rate, this annuity's worth today is closest to: A $16,684 B $18,186 C $25,671. 【答案】 B 【解析】 Two steps: (1) Find the PV of the 10-year annuity: N = 10; I/Y = 9; PMT =-4,000; PV = 0; CPT → PV = 25,670.63. This is the present value as of the end of Year 4; (2) Discount PV of the annuity back four years: N = 4; PMT = 0; FV =-25,670.63; I/Y = 9; CPT → PV = 18,185.72. 第二步，为什么N=4，不是N=5？我认为N=5

老师，这道题难道不是说A与B同时发生的概率P（AB）为3/5吗？odds for的意思就是 ...的概率是什么呀，为什么却是套公式说P（AB）/（1-P（AB））=3/5呢？

老师，上课的时候老师讲过，put option的特点是涨跌都有限，那为什么A不能选？利率 跌倒0的时候不就到了cap的极值了么？

这题怎么理解？

这题怎么理解？

老师，请问scale-free在这里怎么理解？

老师，14题为什么是D0而不是D1，关键词是哪个

老师，什么叫created at the forward price,什么叫created at the swap price？谢谢！

老师，算出来的46500是settlement date的数，为什么不需要折现到现在呢？