Melody

Here is your time line.  5 deposits of   Y units each is made as shown  (I should have used x)

All times must be converted to months.

interest rate is  7.2% / 12 month = 0.6 % per month = 0.006 per month

i=0.006

1+i = 1.006

Now you have to look at what each of these will grow to independently and add them all together.

\(FV=Y*1.006^{48}+Y*1.006^{36}+Y*1.006^{24}+Y*1.006^{12}+Y*1.006^{0}\\ 20000=Y*1.006^{48}+Y*1.006^{36}+Y*1.006^{24}+Y*1.006^{12}+Y\\ 20000=Y(1.006^{48}+1.006^{36}+1.006^{24}+1.006^{12}+1)\\ 20000=Y*5.801723086\\ Y=20000\div5.801723086\\ Y=3447.25\; units\)

So each deposit is R 3447.25

I figure the R must stand for either Real (Brazil) or Rand (South Africa)

I am thinking Rand because you appear to have English as a primary language.

Are you from South Africa?     

Sorry Juriemagic,

I justr read your question for the 100th time only this time I read it properly and it does seem to make sense.

Hang on a bit and I will try to get you and answer.

Guest may be right, I have not looked at what guest has said and i have not done the question myself yet.

More to come.....   

TMga2yb  it is not an equation, it is an expression.  However, the meaning is still not clear. 

5x + 537x + 45y +t46 =?

what does t46 mean?

is it  

\(t^{46}\\ or\\ t\times 46\)

Hi Juriemagic,

I remember seeing this question before and I though I commented the first time round.

I think something is missing from your question.

You have twqo unknowns.

The first that you are trying to find is the regular 4 yearly deposit.

BUT

You know that the investment grows to 20,000 but you are not told how long ths will take. You need to know how long it will take to grow to 20,000 before you can work out a money value for the regular 4 yearly deposit.

Are you given a time anywhere?

Good one Mwashington18        LOL    

It is the same as 'asin'

Hi Juriemagic,

I assume you have been given formulas.

Have you been given a formula called

Future value of an ordinary annuity

as well as one called

Future value of an annuity due?

Maybe you have only been given the first one, or less likely, are you suppose to do it without either of these formula?

The easiest formula is future value of an annuity due but if you don't have it we can use future value of an ordinary annuity almost as easily.

Let me know, and perhaps enter the formula that you are given, and I will then continue.    

Well zero is definitely a number and without it our whole number system would collapse. 

Sir CPhill is still looking for the Roman Zero though.  

How is your quest going Sir CPhill?

I am sure you were told that it is in Sisyphus's boulder so what is the hold up?

Thanks Guest,

I have put this question back on my watchlist.  I shall have a good look at you answer when I get a chance. 

I doubt that very much. 

If you reword it so that it looks legit and then perhaps I will leave it alone :)