Question 301722
If interest is compounded continuously and the interest rate is tripled, what effect will this have on the time required for an investment to double?
-----------
Let interest be "r":
A(t) = P*e^(rt)
Doubles when e^(rt) = 2
rt = ln2
t = (ln(2))/r

-----
Let interest be "3r"
A(t) = P*e^(3rt)
Doubles when e^3rt = 2
3rt = ln2
t = (1/3)(ln(2))/r
---------
The time when the rate was "r" is divided by 3.
==================================================
Cheers,
Stan H.
==================================================