Answer:
It will take 17 years and 245 days.
Explanation:
Giving the following information:
Granny puts $35,000 into a bank account earning 4%. You can't withdraw the money until the balance has doubled.
We need to find the number of years required to achieve $70,000.
We will use a variation of the final value formula:
FV= PV*(1+i)^n
Isolating n:
n=[ln(FV/PV)]/ln(1+r)
n= [ln(70,000/35,000)] / ln(1.04)= 17.67
To be more accurate:
0.67*365= 245 days
It will take 17 years and 245 days.
