Sunday

January 25, 2015

January 25, 2015

Posted by **Cyn** on Thursday, December 3, 2009 at 7:45pm.

- math -
**MathMate**, Thursday, December 3, 2009 at 10:33pmThe rule of 72 gives the rough period as 72/12=6 years.

The accurate calculation is as follows:

P=principal

R=interest rate= 1.12 for 12%

n=number of years required.

So

PR^{n}=2P

R^{n}=2

Take log on both sides,

log(R^{n}=log(2)

n*log(R) = log(2)

n=log(2)/log(R)

=log(2)/log(1.12)

=0.3010/0.0492

=6.116 years.

**Answer this Question**

**Related Questions**

algebra - A total of $12,000 is invested in two funds paying 9% and 11% simple ...

math - Money is invested at two rates of interest. One rate is 8% and the other ...

Algebra 1 --Please help me! - The formula A = P + I shows that the total amount ...

algebra - Money is invested at two rates of interest. One rate is 8% and the ...

Algebra - I invested $42,000 in three funds paying 5%, 7%, and 9% simple ...

math - A.) start by calculating how long it will take you to save enough money ...

math - A student invests two sums of money at 3% and 4% interest, receiving a ...

Algebra - Compare the future amounts (A) you would have if the money were ...

Algebra - Compare the future amounts (A) you would have if the money were ...

Math - Kent invested $5,000 in a retirement plan.He allocated X dollars of the ...