Question

Which of the following is a rational number?

• A. $\sqrt{2}$
• B. $\pi$
• C. $\frac{2}{0}$
• D. 4.8

Answer 1

The correct option is D

4.8

A rational number can be written in the form of $\frac{p}{q}$ where $p$ and $q$ are integers and $q$ is not equal to zero. Rational numbers have their decimal expansions as either terminating or non-terminating but recurring.

$\pi$ = 3.14159265358..., i.e., the digits after decimal point do not terminate and not recurring. Hence it is not rational

$\sqrt{2}$ is approximated to 1.414213562373095..., i.e., it cannot be expressed as a recurring and non-terminating decimal and hence is not rational.

$\frac{2}{0}$ is not defined and for a rational number, the denominator should be non-zero.

4.8 on the other hand, satisfies all the properties of rational numbers.