Which number is not a rational number?

-5 times 4/11

root31

7.608

18.46 continuing

The rules of rational numbers is that if it repeats or ends then it's rational. Answer A is wrong because - 5*4/11 equals - 1.81818181 ... it keeps repeating the same numbers making it rational. Answer C, 7.608 ends, meaning no numbers come after the last one in this case it's 8. Answer D I think would be wrong since it says 18.46 continuing (I assume it's 18.46464646 ...) meaning it repeats which leaves us with the root of 31 which is 5.56776436 ... the number don't stop and they don't repeat making it irrational. So if another question comes up asking if it's rational or irrational just ask yourself does it repeat or end? Or does it go on forever like PI.

I think its the second one, the answer does not have a definite and, and cannot be put into a ratio.