Math Equation...

[shadow123]

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

 

[robots]

hello,

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

thankyou

robots

 

[karmatik]

or

100,000 x (1+0.08)^9

if you want use a calculator

 

[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..)

 

[Insan3]

damn, karmatik beat me to it

 

[shadow123]

Done and dusted.

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

Thanks , much appreciated

 

[2020hindsight]

shadow,
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% (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

 

[rhen]

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.

 

[julius]

e = mc^2

 

[Timmy]

e = mc^2

LOL!

 

[wayneL]

OK, I getting confused!

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

Doh!

 

[kloid]

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

 

[2020hindsight]

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 )

 

[Santob]

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.

 

[wayneL]

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)

 

[Santob]

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.

 

[wayneL]

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

 

[2020hindsight]

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% each (compounding), then you'll have doubled your money. Easy if you say it fast.

So is there a difference between ^ and x in your business?

In the bridge building game, it seems ^ = X

gee whiz wayne, I would have thought you'd double check before double posting.

 

[wayneL]

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

 

[Buddy]

42......