Question

Is 0.135135135135...... a irrational number?

Answer 1

It is not an irrational number.  In this number, the pattern is 135 repeating.  Since it repeats in a certain pattern, it is rational.

Answer 2

An irrational number is a number that cannot be written in the form a/b or fractional form
this is repeating so we can just draw a vinculum over the repeting part (135)
it would be represented as <u />
<u />   ___
0.135

this is a rational number