Is 1/3 a rational or irrational number? Prealgebra Arithmetic and Completing Problems Rational and Irrational Numbers 1 Answer Konstantinos Michailidis Apr 22, 2016 By definition, a rational number is a number #q# that can be written as a fraction in the form #q = a / b# where a and b are integers and #b ≠ 0# . Hence #1 / 3# is rational Answer link Related questions Is 7.3 a rational number? Is -12 a rational number? What is the difference between real numbers and rational numbers? Are some rational numbers integers? Is #2/3# a rational number? Is 0 a rational or irrational number? Is 1/2 a real and rational number? Why do rational numbers repeat? How do irrational numbers differ from rational numbers? Is 0 an irrational number? See all questions in Rational and Irrational Numbers Impact of this question 66534 views around the world You can reuse this answer Creative Commons License