Question

Which of the following is/are irrational numbers?

• A. $\sqrt{2}$
• B. $\sqrt{3}$
• C. $\sqrt{4}$
• D. $\sqrt{5}$

Answer 1

Answer: (A), (B), (D)

The correct options are
A $\sqrt{2}$
B $\sqrt{3}$
D $\sqrt{5}$

An irrational number is a number that cannot be written in the $\frac{p}{q}$, where and p and q are integers and $q\ne 0$.

a) $\sqrt{2}$ is non terminating and non repeating. It cannot be written in the $\frac{p}{q}$ form.

b) $\sqrt{3}$ is non terminating and non repeating. It cannot be written in the $\frac{p}{q}$ form.

c) $\sqrt{4}$ is actually 2. It can be written in the $\frac{p}{q}$ form.

d) $\sqrt{5}$ is non terminating and non repeating. It cannot be written in the $\frac{p}{q}$ form.

Therefore, $\sqrt{2}$, $\sqrt{3}$ and $\sqrt{5}$ are irrational numbers among the given options.