To double takes, don't ask me why, 70/x years where x is the interest rate, so 14 years give or take a month or two.
It will take 18 years.
Nine years at 8%
As a rough guide to double any amount compounded annually, divide 70 by the interest rate. In this case that is 14 years.
Twelve years at 6%
Nine years at 8%
There is what's called the "rule of 72" which states, you divide the percent into 72 and that tells you how log it takes to double your money. For example, 4.6 goes into 72 15.65 times. So, it would take 15.65 years to double your money. That's not too good of an investment. 72 ÷ 4.6 = 15.65
i would say about a week!!!!
20 years
8 years.
72/9 ie 8 years
Pro athletes do it in about 9 seconds. For an average Joe, expect almost the double.
9.0065 years.