Question

Which number is irrational?

Answer 1

Yes, it is B.

You can express the others as fractions, but not the square root of 5.

Answer 2

Irrational numbers are number that can't be written in a/b form where a and b are integers and b≠0


if it repeats, it can be written as a fraction
if it terminates, it can also be written as a fraction

if you have a square root that doesn't simplify nicely, we assume it to be irrational

so

A. 0.454545=45/99
B. irrational
C. 7/9
D. 3/10



yep, it's √5