The answer is Irrational.
The other answer is incorrect, as the answer is said to be rational.
When you see decimals that go on forever, you can identify them two ways: one is when the decimal repeats (ex. 3.333333 or 5.575757). These are rational. Irrational non-terminating decimals do not have a pattern (ex. 5.7164927172917…) these cannot be converted to a fraction, and therefore is irrational.