posted by anonymous .
marcia has $220,000 saved for her retirement. How long will it take for the investment to double in value if it earns 6% interest compounded continuously?
for the exact answer (11.56 yrs), or use the "rule of 72*" and get about 12 years.
*The product of the annual interest rate and the number of years must be 72 to double your money.
i didn't get the right answer :[
the answer must be 139 months
In your case,
ln2 = 0.06t
= 11.5524 years x 12 months