{daily.math} Puzzle

If 33 is six years older than 27, then 27 is six years younger than 33. Being twenty-seven years old, I know that 27 is not necessarily one year younger than 28. In fact, 27 can still be two years older than 28. If 31 is only three years older than 28, how older (younger) is 31 when compared to 27?

When answering the puzzle, do not provide any solutions. I will provide the correct answer, at least after four comments.