Answer:
It will take 14.29 years for your bank balance to double from $1,000 to $2,000.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:

In which E are the earnings, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
After t years, the total amount of money is:
.
If the interest rate is 7%, how many years will it take for your bank balance to double from $1,000 to $2,000?
We have that 
We want to find t when E = 1000, so
.




It will take 14.29 years for your bank balance to double from $1,000 to $2,000.