All of the following are rational numbers except

2/3
1.33 repeated
−16
3.

asap

3.14159...

A irrational number can't be written as a fraction so its not 2/3 or -16, irrational numbers aren't repeating so it's not 1.33. 

Rational numbers can be represented in the form a/b where b is not equal to zero

2/3 is in a/b form
1.333333 repeated=1 and 1/3 or 4/3
-16=-16/1
3.141592... is obviously pi which is one of the most popular irrational numbers

answer is 3.141592...