Question

Which of the following is not a rational number

square root 100
-3/8
square root 2
-0.135

Answer 1

√2

Explanation:

As a fraction, 2 is 2/1

Oh no, there is always an odd exponent. So it could not have been made by squaring a rational number! This means that the value that was squared to make 2 (ie the square root of 2) cannot be a rational number. In other words, the square root of 2 is irrational.