Question: is 3/13 rational or irrational?
Answer: For example 1/3 = 0.333..., 10/11 = 0.909090... and 3/13 = 0.230769230769... When you write a rational number in decimal form you obtain either a decimal that stops after a finite number of terms, or a pattern that repeats as in the latter three examples. Not all numbers are integers or rational numbers.