You are currently age 20,you will start work at 25 and work

来源：学生作业帮编辑：灵鹊做题网作业帮分类：英语作业时间：2024/04/27 09:16:37

You are currently age 20,you will start work at 25 and work until age 65,then you will retire and live until age 90.you spend $30,000 per year to live now(in today's dollars).your wish is to have the same amout to spend in retirement( same lifestyle).Inflation will be 2% ( compounded annually) all the time and you can save and invest money at 6%( compounded semi-annually) all the time.how much do you need to save each month starting at age 25 to age 65(same amout each time) in order to have a nice retirement?相关公式：future value=payment[(1+i)*n-(1+g)*n/i-g]present value=payment[1-(1+g)*n(1+i)*-n/i-g]
你现在20岁，25岁开始工作，65岁退休，90岁死亡。你每年花30，000元，（在如今的通胀）你希望你能拥有相同的花费当你退休以后（应该是说，退休以后依然能每年花上这么多钱）。通胀率2%每年，你可以获得6%的节约和投资回报率。（按每半年计算）。在你25岁到65岁期间每月要节约和投资多少钱才能保证你的退休后的生活。

1.20岁每年3万,至65岁退休后当年需花费3*（1+2%）^45 = 7.3万
2.pv = 7.3 + 7.3（1+2%）/(1+6%) + 7.3（1+2%）^2/(1+6%)^2 +.+7.3（1+2%）^24/(1+6%)^24 = 15.95万
3.fv=15.95 n=30 I=6% pv =0,求出pmt=1.16（这是按年计算的）,得出结果后除以12,可得到每个月的投资金额为966.67元.
再问：还是有点没看懂，请问24和n=30是怎么来的？还有题目中的单位需要转换么？（因为iflation是compound annual， invest是compound semi-annual）中文不懂怎么表达，麻烦了
再答：画个时间线。英文没仔细看：）如果iflation是compound annual， invest是compound semi-annual，那就得转换一下，把semi-annual转换成annual的，89-65=25，我理解的是年初拿到钱，活到90就是89岁年初有一笔payout，30就是工作30年65-25
再问： 65-25等于40呀！而且有用到我之前说的公式么？投资的那40年中也存在着inflation，只单纯的用 fv，n，I ，求出pmt对么？是不是这时候该用我补充问题里用的公式？还有那一大串的15. 95怎么求呀，太多数字了，有计算公式么？：）好多问题帮我再分析分析吧
再答：

are you at work Are you at work or at where do you work and where are you work ---where will you start your work after graduation?---Mom,it Will it be c___ for you to start work tomorrow? Will it be convenient for you to start work tomorrow? You work hard and often successful.you are good at making or ____(只要)you work hard,you will be successful at are you still work? are you through work Work hard at your lessons and you will pass the mid-examinat Work hard at your lessons and you will pass the examination.