问题 问答题

系列现金流现值的计算

答案

参考答案:(1)等额系列现金流的终值
先付年金是指在每期期初支付的年金。设每年支付的金额为A,利率为r,期数为n,先付年金终值为TVb,先付年金终值的计算公式为:
TVb=A(1+r)+A(1+r)2+…+A(1+r)n (3-10)
后付年金又称普通年金,是指各期期末支付的年金。按复利计算的后付年金终值TVa为:
TVa=A+A(1+r)+A(1+r)2+…+A(1+r)n-1 (3-11)
(2)不等额系列现金流的终值
不等额系列现金流的金融工具一般指偿债基金。所谓偿债基金是指为使年金终值达到既定金额每年应支付的年金数额。偿债基金的基本机制是这样的:首先将债务总额根据偿还期限的期数(例如偿还期限为3年,按月偿还,则期数为36)分成等额的部分,然后将各部分金额平均分配到各期进行偿还,这里要注意的是,由于利息的存在,各期实际存入的金额要小于各期的分配金额,只要当借贷期限届满时,该金额的本息和等于各期的分配金额即可。
根据后付年金终值计算公式:
[*]
可知各期应偿付的金额为: [*] (3-12)
式中的[*]是后付年金终值系数的倒数,称为偿债基金系数。该公式在金融实务和财务理论中具有广泛的应用,需要重点掌握。

选择题
单项选择题

The Supreme Court will hear arguments about the use of public money for the private schooling of children with special needs. It’s interesting to note what’s not at issue: namely, that when a public school system is unable to provide an appropriate education, it is obligated to pay the costs of private school. Too bad poor children don’t have that unshakable right; if they did, there would be no controversy about the District program that gives vouchers to low-income children to attend private schools.

The case to be heard by the court hinges on whether parents have to enroll a child with special needs in public school before the child can attend private school at public expense. Special-education advocates say students shouldn’t have to waste time before being placed in a setting that best suits their needs, while school boards worry about a ruling that could amount to an unfettered fight to private schooling at public expense. What strikes us about the emotionally charged debate is the acceptance by both sides that sometimes it is appropriate to use public money to pay for a child to go to a private school. So, why all the arguments about the approximately$14 million for a federally funded program that lets 1,700 D. C. students attend private schools instead of failing public schools

To hear critics of the D. C. Opportunity Scholarship Program tell it, the use of public money for private schooling is as unprecedented as it is undesirable. In addition to the billions of dollars spent annually on private school tuitions for students with disabilities, private schools get public money for books, technology and teacher training. As long as the money is seen as benefiting the child, it is considered a proper, even desirable, use of public dollars.

Don’t get us wrong. We’re not arguing for the unilateral right of parents to enroll their sons and daughters in any school they wish with the taxpayers picking up the bill. Abuse of special-education policies has contributed to increased costs that threaten to take needed money from general public education funds. Safeguards are needed. Public schools should be pressed to do a better job for students with disabilities and students without. But there are schools in Washington where statistics show that failure is almost guaranteed. If a school system can’t educate a child—whether because of acute special needs or its own historical failings—why should that child not have options for a " free appropriate public education "

Which of the following is TRUE about the special-education advocates’ opinion()

A. They ply believe that children should be put directly into the private schools

B.They think that children should try out both places before making decisions

C. They don’t feel there is still a need to argue about this problem any more

D. They hold the opinion that parents can make decisions for their children