Answer:
1/5 is a rational number.
Step-by-step explanation:
Natural numbers are the numbers you use to count with (1, 2, 3, etc.). Nobody uses fractions while counting whole objects unless they think they're funny and want to stall, so 1/5 wouldn't be a rational number.
Whole numbers are the exact same as natural numbers, but with the addition of the number 0 (think about it, no one starts from zero when counting).
Integers include whole numbers as well as their opposites (for example, the opposite of 4 is –4).
As a basic rule of thumb, if the number includes a fraction or a decimal point of any kind, it would be a rational number.