Q:
Write a function in Java taking string and returning string, which is
“3” if the input string represents a positive number evenly divisible by 3
“5" if the input string represents a positive number evenly divisible by 5
“15” if the input string represents a positive number evenly divisible by 15
and the input string itself otherwise.

A:
Here's one possible implementation of a function that takes a string as input and returns a string as output, based on the conditions you've described:

• Use tabs for indentation.
• Add a newline to the end of every file.
• There must not be whitespace characters at the end of a line