Which of the following is an irrational number?

Question

Responses
A square root of 25
B square root of 13
C 4.2
D 1.8

Answer 1

The irrational number among the options provided is:

B: square root of 13

The square root of 13 is an irrational number because it cannot be expressed as a fraction of two integers. In contrast, the square root of 25 is a rational number (5), and both 4.2 and 1.8 are also rational numbers.