Thursday

January 29, 2015

January 29, 2015

Posted by **Sarah** on Sunday, November 21, 2010 at 8:09pm.

- Math -
**MathMate**, Sunday, November 21, 2010 at 10:43pmFor r=0.095, with normal compound interest, compounded yearly, the number of years to double at a rate of r% is ln(2)/ln(1+r)=ln(2)/ln(1.095)=7.638 years.

from A=P(1+r)^n

take ln both sides,

ln(A/P)=n ln(1+r)

n=ln(2)/ln(1+r)

With continuous compounding,

A=Pe^{rn}

Take logs

ln(A/P)=e^{rn}

ln(2)=rn

n=ln(2)/r

=ln(2)/0.095

=7.296 years

**Answer this Question**

**Related Questions**

math - marcia has $220,000 saved for her retirement. How long will it take for ...

math - How long will it take for an investment of $13,000 to double if the ...

How long will it take the investment to double? - $3,600 is invested in an ...

Math - If $8,500 is invested at 6% compounded continuously, how long will it ...

Math - How long it will take for an investment of 2000 dollars to double in ...

math - How long it will take for an investment of 1000 dollars to double in ...

Math - If $8,500 is invested at 6% compounded continuously, how long will it ...

Calculus - An investment grows ar a rate of 2.5% each year compounded ...

Math - exponential function - If an account that earns interest compounded ...

precalc - A $5000 investment earns 7.2% annual interest, and an $8000 investment...