It will take 20 years.
It is approx 8.66%
331/3 percent simple interest will double any amount in 3 years.
8 years.
11 years
As a rough guide to double any amount compounded annually, divide 70 by the interest rate. In this case that is 14 years.
20 YEARS
There's a rule of thumb for "double your money" problems: Time = 70/interest rate, so in this case approx 7 years.
It is approx 8.66%
331/3 percent simple interest will double any amount in 3 years.
33 years
It will take 25 years for a 100 to double check if you have a simple interest of 4 percent.
It will take 18 years.
If the interest rate was eight percent, it would take about 9 years to double your principle.
Nine years at 8%
Use the "rule of 72"...simply put, using compound interest you take the number 72 and divide it by the interest rate. Thus, at 5% the time to double is 14.4 years. This formula can be used for calculating a "double" for any interest rate using the same mathematical procedure.
10 years
the equation for compound interest is Pe^(rt) the principal you want in the end is twice that of the original 12,000 plugging in and solving you get 12,000=6000e^(.13t) t = 5.33 years