A simple formula can help you estimate the number of years required to double your money. It's called the rule of 72. You simply divide 72 by the interest rate (without the percent sign). For example, with an interest rate of 4%, your money would double in approximately 72+4, or 18 years. Complete parts (a) through (e).a) How many years would it take $1000 to double at an interest rate of 2%?years