这道题真的是搞不懂呢，其他同学的提问我也看了，还是没明白……问题如下图：
选项：
A. 
B. 
C. 
解释：
菲菲_品职助教 · 2018年12月04日
同学你好，这其实考的就是CDs。期初投资2万，每年会产生700的利息，然后将这700的利息按月进行再投资，最后让我们计算终值。大概讲的就是这么个意思。你根据这个思路再来想想看~
絮飛W涙 · 2018年12月04日
那第二步每年七百的利息是不是要用计算器按四次？不能一次按出来么？
菲菲_品职助教 · 2018年12月05日
可以用计算器哦。先单独计算利息这部分：N=4; I/Y=[(1+2%/12)^12-1]*100; PMT=-700; PV=0; CPT FV=2885.92。其中I/Y要转换成EAR（即上面表达式）。 再加上之前的本金20000即可得到最后的正确答案。
絮飛W涙 · 2018年12月05日
我可能傻了……我也算出来2885结果我脑子一呆以为答案应该是28852……我可能疯了已经……谢谢菲菲超爱你
菲菲_品职助教 · 2018年12月05日
哈哈哈 没关系 有时候是会这样的～ 注意休息 加油加油💪🏻
xkacmzz · 2018年12月09日
老师，为什么有的地方算IY要用月度换算的EAR，N=4。而不能用N=48，IY=2/12。比如最开始的课后题6还是7题，3%是否用EAR的问题。已经完全晕掉了TT
菲菲_品职助教 · 2018年12月10日
@xkacmzz，具体用什么是要看题目给的条件以及需要计算的是什么哦。你可以把你搞不清楚的几道题目汇总一下截个图一起提问，然后我再帮你总结一下~
NO.PZ2017092702000019问题如下A client invests €20,000 in a four-yecertificate of posit (C thannually pays interest of 3.5%. The annuinterest payments are automatically reinvestein a separate savings account a stateannuinterest rate of 2% compounmonthly. maturity, the value of the combineasset is closest to:A.€21,670.B.€22,890.C.€22,950. B is correct, the following cash flows show:The four annuinterest payments are baseon the Cs 3.5% annurate. The first payment grows 2.0% compounmonthly for three years (where FV is future value): FVN = €700(1 +0.02/12 )3×12 FVN = 743.25 The seconpayment grows 2.0% compounmonthly for two years: FVN = €700(1 +0.02/12 )2×12 FVN = 728.54 The thirpayment grows 2.0% compounmonthly for one year: FVN = €700(1 +0.02/12 )1×12 FVN=714.13The fourth payment is paithe enof Ye4. Its future value is €700. The sum of all future value payments is follows:根据EAR的公式（1+2%/12）^12=1+EAR，得到EAR=2.0184%。然后1. 首先按照年金的方式来计算利息再投资的终值N=4，I/Y=2.0184，PV=0，PMT=700，CPT FV=-2885.9208；其中700是20,000每年按照3.5%产生的利息，I/Y是转化的EAR，因为利息（PMT）的频率也是一年一付的。2. 然后把期初的这20,000再加回去，得到22,885.92。（和B有写出入是因为四舍五入的问题，但不影响选出答案） 老师，2/12这个不是把月计的利率转成年计吗，和E的区别在哪？谢谢
NO.PZ2017092702000019 问题如下 A client invests €20,000 in a four-yecertificate of posit (C thannually pays interest of 3.5%. The annuinterest payments are automatically reinvestein a separate savings account a stateannuinterest rate of 2% compounmonthly. maturity, the value of the combineasset is closest to: A.€21,670. B.€22,890. C.€22,950. B is correct, the following cash flows show:The four annuinterest payments are baseon the Cs 3.5% annurate. The first payment grows 2.0% compounmonthly for three years (where FV is future value): FVN = €700(1 +0.02/12 )3×12 FVN = 743.25 The seconpayment grows 2.0% compounmonthly for two years: FVN = €700(1 +0.02/12 )2×12 FVN = 728.54 The thirpayment grows 2.0% compounmonthly for one year: FVN = €700(1 +0.02/12 )1×12 FVN=714.13The fourth payment is paithe enof Ye4. Its future value is €700. The sum of all future value payments is follows:根据EAR的公式（1+2%/12）^12=1+EAR，得到EAR=2.0184%。然后1. 首先按照年金的方式来计算利息再投资的终值N=4，I/Y=2.0184，PV=0，PMT=700，CPT FV=-2885.9208；其中700是20,000每年按照3.5%产生的利息，I/Y是转化的EAR，因为利息（PMT）的频率也是一年一付的。2. 然后把期初的这20,000再加回去，得到22,885.92。（和B有写出入是因为四舍五入的问题，但不影响选出答案） 这道题第一年的利息是700， 第二年的不应该是20700*0.035 = 724.5吗？这样的话，每一年的PMT就不是固定的700了。这个地方没太搞懂，希望老师解析一下，谢谢
NO.PZ2017092702000019 问题如下 A client invests €20,000 in a four-yecertificate of posit (C thannually pays interest of 3.5%. The annuinterest payments are automatically reinvestein a separate savings account a stateannuinterest rate of 2% compounmonthly. maturity, the value of the combineasset is closest to: A.€21,670. B.€22,890. C.€22,950. B is correct, the following cash flows show:The four annuinterest payments are baseon the Cs 3.5% annurate. The first payment grows 2.0% compounmonthly for three years (where FV is future value): FVN = €700(1 +0.02/12 )3×12 FVN = 743.25 The seconpayment grows 2.0% compounmonthly for two years: FVN = €700(1 +0.02/12 )2×12 FVN = 728.54 The thirpayment grows 2.0% compounmonthly for one year: FVN = €700(1 +0.02/12 )1×12 FVN=714.13The fourth payment is paithe enof Ye4. Its future value is €700. The sum of all future value payments is follows:根据EAR的公式（1+2%/12）^12=1+EAR，得到EAR=2.0184%。然后1. 首先按照年金的方式来计算利息再投资的终值N=4，I/Y=2.0184，PV=0，PMT=700，CPT FV=-2885.9208；其中700是20,000每年按照3.5%产生的利息，I/Y是转化的EAR，因为利息（PMT）的频率也是一年一付的。2. 然后把期初的这20,000再加回去，得到22,885.92。（和B有写出入是因为四舍五入的问题，但不影响选出答案） 我理解可以将利息的再投资作为年金来计算，但是我算的时候我直接使用的I/Y是2%/12因为是以一个月为期复利的，为什么不能用这个作为I/Y而是需要算它的EAR在带入计算器去算？
NO.PZ2017092702000019问题如下A client invests €20,000 in a four-yecertificate of posit (C thannually pays interest of 3.5%. The annuinterest payments are automatically reinvestein a separate savings account a stateannuinterest rate of 2% compounmonthly. maturity, the value of the combineasset is closest to:A.€21,670.B.€22,890.C.€22,950. B is correct, the following cash flows show:The four annuinterest payments are baseon the Cs 3.5% annurate. The first payment grows 2.0% compounmonthly for three years (where FV is future value): FVN = €700(1 +0.02/12 )3×12 FVN = 743.25 The seconpayment grows 2.0% compounmonthly for two years: FVN = €700(1 +0.02/12 )2×12 FVN = 728.54 The thirpayment grows 2.0% compounmonthly for one year: FVN = €700(1 +0.02/12 )1×12 FVN=714.13The fourth payment is paithe enof Ye4. Its future value is €700. The sum of all future value payments is follows:根据EAR的公式（1+2%/12）^12=1+EAR，得到EAR=2.0184%。然后1. 首先按照年金的方式来计算利息再投资的终值N=4，I/Y=2.0184，PV=0，PMT=700，CPT FV=-2885.9208；其中700是20,000每年按照3.5%产生的利息，I/Y是转化的EAR，因为利息（PMT）的频率也是一年一付的。2. 然后把期初的这20,000再加回去，得到22,885.92。（和B有写出入是因为四舍五入的问题，但不影响选出答案） 这题为什么不是把前三笔700求他们的FV PMT=700 PV=0 I/Y=2%/12 n=3*12 求FV 之后加20000+700 为啥这样不对呢
NO.PZ2017092702000019 问题如下 A client invests €20,000 in a four-yecertificate of posit (C thannually pays interest of 3.5%. The annuinterest payments are automatically reinvestein a separate savings account a stateannuinterest rate of 2% compounmonthly. maturity, the value of the combineasset is closest to: A.€21,670. B.€22,890. C.€22,950. B is correct, the following cash flows show:The four annuinterest payments are baseon the Cs 3.5% annurate. The first payment grows 2.0% compounmonthly for three years (where FV is future value): FVN = €700(1 +0.02/12 )3×12 FVN = 743.25 The seconpayment grows 2.0% compounmonthly for two years: FVN = €700(1 +0.02/12 )2×12 FVN = 728.54 The thirpayment grows 2.0% compounmonthly for one year: FVN = €700(1 +0.02/12 )1×12 FVN=714.13The fourth payment is paithe enof Ye4. Its future value is €700. The sum of all future value payments is follows:根据EAR的公式（1+2%/12）^12=1+EAR，得到EAR=2.0184%。然后1. 首先按照年金的方式来计算利息再投资的终值N=4，I/Y=2.0184，PV=0，PMT=700，CPT FV=-2885.9208；其中700是20,000每年按照3.5%产生的利息，I/Y是转化的EAR，因为利息（PMT）的频率也是一年一付的。2. 然后把期初的这20,000再加回去，得到22,885.92。（和B有写出入是因为四舍五入的问题，但不影响选出答案） 如题。