Which of the following numbers is a rational number?

easy MCQ 1 mark Class 10 · Mathematics · Real Numbers

Answer

0.75

The correct answer is $0.75$ — Hence $0.75$ is the only rational number among the options.

Step-by-step solution

Recall that a rational number can be written as a fraction $\frac{p}{q}$ where $p, q$ are integers and $q \neq = 0$ .
A terminating decimal is a special case of a fraction whose denominator after simplification has only the prime factors $2$ and $5$ .
$0.75$ terminates after two decimal places, so it can be written as $\frac{75}{100} = \frac{3}{4}$ , a ratio of integers.
$2$ and $π$ are known to be irrational, and $3.14159 \dots$ is a non‑terminating non‑repeating decimal, also irrational.
Hence $0.75$ is the only rational number among the options.

Common mistake: Assuming any decimal is irrational because it looks non‑repeating

Concept tested: Definition of rational numbers