Math Equation... - Aussie Stock Forums

1. Math Equation...

My apologies for asking a math question

buuuuuuttttttt

what would be the equation per se if :

person (a) has 100 000\$ , gets 8 % each year for hypothetically 9 years

eg 8 % of 100 000 , then 8 percent of that etc

2. Re: Math Equation...

hello,

http://www.banksite.com/calc/savings

thankyou

robots

3. Re: Math Equation...

or

100,000 x (1+0.08)^9

if you want use a calculator

4. Re: Math Equation...

or A=P(1+i)^n if you want a written formula.

A = Amount
P = Principal
i = Interest Rate (in decimal format)
n = No of Interest Periods (If Yearly, 1 per year, Monthly, 12 per year, etc..)

5. Re: Math Equation...

damn, karmatik beat me to it

6. Re: Math Equation...

Done and dusted.

I will have a beer on each of you for a toast

Thanks , much appreciated

7. Re: Math Equation...

here's one
rule of 72.
1.02 ^ 36 = 2.0 (note 2 x 36 = 72)
1.03 ^ 24 = 2.0 (note 3 x 24 = 72)
1.04 ^ 18 = 2.0 (note 4 x 18 = 72)
1.06 ^ 12 = 2.0 (note 6 x 12 = 72)
1.08 ^ 9 = 2.0 (note 8 x 9 = 72)
1.09 ^ 8 = 2.0 (note 9 x 8 = 72)
1.12 ^ 6 = 2.0 (note 12 x 6 = 72)

36 years at 2&#37; (compound) will double your money
24 years at 3% ditto etc etc
so
9 years at 8% (where 9 x 8 = 72) will double your money

8. Re: Math Equation...

Originally Posted by Insan3
or A=P(1+i)^n if you want a written formula.

A = Amount
P = Principal
i = Interest Rate (in decimal format)
n = No of Interest Periods (If Yearly, 1 per year, Monthly, 12 per year, etc..)
I guess just for "completeness" of sorts, we should add that the interest rate, i, is the effective interest rate which may or may not be the p.a. quoted.
eg for 8%pa compounding annually, i=0.08 and n=number of years (as above.)
compounding semiannually, i=0.04 and n=2xnumber of years
compounding quarterly, i=0.02 and n=4xnumber of years
etc etc
you've got the message
the rule of 72 is good but it's just an approximation.

e = mc^2

10. Re: Math Equation...

Originally Posted by julius
e = mc^2
LOL!

11. Re: Math Equation...

OK, I getting confused!

What does "^" signify in these equations? It seems to metamorphose its function throughout this thread.

Doh!

12. Re: Math Equation...

Originally Posted by wayneL
OK, I getting confused!

What does "^" signify in these equations? It seems to metamorphose its function throughout this thread.

Doh!
^ means "to the power of" e.g. 4^3 is 4 x 4 x 4.

Kloid

13. Re: Math Equation...

Originally Posted by rhen
the rule of 72 is good but it's just an approximation.
next question rhen
is there a difference between 2 and 2.0 (in your line of business)
(there is in mine )

14. Re: Math Equation...

Originally Posted by 2020hindsight
next question rhen
is there a difference between 2 and 2.0 (in your line of business)
(there is in mine )
Only for very large values of 2 - now a mathermatician would appreciate that joke.

15. Re: Math Equation...

Originally Posted by 2020hindsight
next question rhen
is there a difference between 2 and 2.0 (in your line of business)
(there is in mine )
So is there a difference between ^ and x in your business?
(There is in mine)

16. Re: Math Equation...

Originally Posted by wayneL
So is there a difference between ^ and x in your business?
(There is in mine)
I'd be concerned if there wasn't a difference, in any situation.

17. Re: Math Equation...

Originally Posted by Santob
I'd be concerned if there wasn't a difference, in any situation.
Yer, but
1.02 ^ 36 = 2.0 (note 2 x 36 = 72)
1.03 ^ 24 = 2.0 (note 3 x 24 = 72)
1.04 ^ 18 = 2.0 (note 4 x 18 = 72)
1.06 ^ 12 = 2.0 (note 6 x 12 = 72)
1.08 ^ 9 = 2.0 (note 8 x 9 = 72)
1.09 ^ 8 = 2.0 (note 9 x 8 = 72)
1.12 ^ 6 = 2.0 (note 12 x 6 = 72)
In the bridge building game, it seems ^ = X

18. Re: Math Equation...

Originally Posted by Santob
I'd be concerned if there wasn't a difference, in any situation.
santob and wayne,
me too (concerned etc)
then again there are such things as mistakes.

and wayne, I think you'll find you have made one in accusing me of getting "x" and "^" confused.

btw, here's that table
and the difference between 2 and 2.0 is the fact that you are accurate to 2 significant figures in the second case. (note that the approxmation is evident when you take it to three significant figures. )

btw, that rule of 72 also works for trades obviously.

i.e. between now and end of financial year, if you make a trade each week for 12 weeks that grows by 6&#37; each (compounding), then you'll have doubled your money. Easy if you say it fast.
Originally Posted by wayne
So is there a difference between ^ and x in your business?
Originally Posted by wayne
In the bridge building game, it seems ^ = X
gee whiz wayne, I would have thought you'd double check before double posting.

19. Re: Math Equation...

PM me a list of bridges you've built; just so I know for if I ever come back to Oz.

20. Re: Math Equation...

42......

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