Answer:
The answer to this question is the "years--;".
Explanation:
In the given question code the if we define the years--; and the rate of interest in the code so this program will return a value for example if we give rate of interest or rate to value 5 then the output of the code is 26532.977051 because it returns the double that is a floating-point value. So the missing code for this question is "years--;".