A float typically refers to a number that has a decimal point, representing a fractional value. In the given options, "5/22" is not a float, as it is a fraction. "3:30" suggests a time rather than a numeric value, "N-5" is an alphanumeric expression, and "May 3- May 5" represents dates. None of these options is a float.
If you need an example of a float, it would be something like "3.14" or "2.75". However, based on your options, none qualify as a float.