Question

What is the irrational number in This set: 12.89, square root of 12 and 12/144 ?

Answer 1

Good night, 

Irrational numbers are those that can't be expressed as a fraction:

12.89 can be expressed as: $\frac{1289}{100}$

$\frac{12}{144}= \frac{1}{12}$

The above numbers can be expressed as a fraction, then the logical answer is: $\sqrt{12}$

But we will check the answer: 

$\sqrt{12}= \sqrt{2^{2}*3 } =2* \sqrt{3} =3.4641016...$

As you can see we can't express that number as a fraction, so that is te correct answer.