If you deposit $1,000 into a savings account that pays you 5% interest per year, approximately how long will it take to double your money? If you deposit $1,000 into a savings account that pays you 5% interest per year, approximately how long will it take to double your money?"

It will take 14 years.

Explanation:

Imagine you are Julie at year cero about to purchase eleven acres of land. The seller tells you that in X amount of years it will value $34686 because it increases 5% each year. He also tells you that according to the Present Value formula, the eleven acres are worth today $15890.

The formula is:

PV=Ct/[ (1+r) ^n]

Ct = cash flow at t time

r = rate

n = period of time

To calculate how many years it will be worth $34686 you need to isolate n from the PV formula

n=[ln (Ct/PV) ]/ln (1+r)

n=ln (34686/15890) / ln (1+0,05)

n=16

Giving the following information, we need to calculate how many years will take to the investment to duplicate:

I = $1000

I=5%

To calculate we are going to use the Present value formula:

PV=Ct/[ (1+r) ^n]

Ct = cash flow at t time

r = rate

n = period of time

To calculate how many years it will take to duplicate we need to isolate n from the PV formula

n=[ln (Ct/PV) ]/ln (1+r)

n=ln (2000/1000) / ln (1+0,05)

n=14