How long will it take any sum to double itself a. With a 12 percent simple interest rate? b. With a 12 percent interest rate, compounded annually? c. With a 12 percent interest rate, compounded continously? a. It will take any sum year(s) to double itself with a 12 percent simple interest rate. (Type an integer or decimal rounded to one decimal place as needed.) b. It will take any sum year(s) to double itself with a 12 percent interest rate, compounded annually. (Round up to the nearest year. Type an integer or a decimal.)