Answer:
Interest rate of 7%.
Step-by-step explanation:
The compound interest formula is given by:
Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
In this question:
We want to find t for which when
. So
So a interest rate of 7%.
