Class 9 Maths Chapter 3 MCQs with Answers – The World of Numbers

Class 9 Maths Chapter 3 MCQs

Question 1. Which of the following is a rational number?

A. √2

B. √3

C. 7/9

D. π

Question 2. Which of the following is an irrational number?

A. 3/5

B. 0.25

C. √7

D. −4

Question 3. What is the decimal expansion of 1/4?

A. 0.25

B. 0.4

C. 0.14

D. 0.125

Question 4. Which fraction has a terminating decimal expansion?

A. 1/3

B. 2/7

C. 5/8

D. 4/9

Question 5. Which of the following is an integer but not a natural number, assuming natural numbers begin at 1?

A. 5

B. 1

C. 0

D. 7

Question 6. Which statement about rational numbers is correct?

A. Every rational number is an integer.

B. Every integer is a rational number.

C. No negative number is rational.

D. Every rational number is irrational.

Question 7. Which of the following has a non-terminating, recurring decimal expansion?

A. 1/8

B. 3/20

C. 2/11

D. 7/25

Question 8. What is the value of √81?

A. 8

B. 9

C. 18

D. 40.5

Question 9. Which of the following is a perfect square?

A. 18

B. 27

C. 36

D. 45

Question 10. Which of the following numbers lies between 2 and 3?

A. √3

B. √5

C. √10

D. √16

Question 11. What is the simplest form of √50?

A. 2√5

B. 5√2

C. 10√5

D. 25√2

Question 12. Which of the following fractions is equivalent to 3/4?

A. 6/10

B. 9/12

C. 12/20

D. 15/24

Question 13. Which decimal represents the rational number 1/3?

A. 0.3

B. 0.33 exactly

C. 0.333…

D. 0.303003000…

Question 14. Which statement about irrational numbers is correct?

A. Their decimal expansions always terminate.

B. Their decimal expansions eventually repeat.

C. They cannot be represented on the number line.

D. Their decimal expansions are non-terminating and non-recurring.

Question 15. Which number lies between 1/2 and 3/4?

A. 1/4

B. 5/8

C. 7/8

D. 4/5

Answer Key – Class 9 Maths Chapter 3 MCQs

1. Question 1 — Correct Answer: C. 7/9 A rational number can be expressed as p/q, where p and q are integers and q ≠ 0. Therefore, 7/9 is rational.
2. Question 2 — Correct Answer: C. √7 Since 7 is not a perfect square, √7 is an irrational number.
3. Question 3 — Correct Answer: A. 0.25 Dividing 1 by 4 gives 0.25.
4. Question 4 — Correct Answer: C. 5/8 5/8 = 0.625. Its decimal expansion terminates.
5. Question 5 — Correct Answer: C. 0 Assuming natural numbers begin at 1, zero is an integer but not a natural number.
6. Question 6 — Correct Answer: B. Every integer is a rational number. Every integer can be written as a fraction with denominator 1. For example, 5 = 5/1.
7. Question 7 — Correct Answer: C. 2/11 2/11 = 0.181818… The digits 18 repeat indefinitely.
8. Question 8 — Correct Answer: B. 9 Since 9 × 9 = 81, √81 = 9.
9. Question 9 — Correct Answer: C. 36 36 is a perfect square because 6² = 36.
10. Question 10 — Correct Answer: B. √5 Since 2² = 4 and 3² = 9, and 4 < 5 < 9, √5 lies between 2 and 3.
11. Question 11 — Correct Answer: B. 5√2 √50 = √(25 × 2) = √25 × √2 = 5√2.
12. Question 12 — Correct Answer: B. 9/12 Multiplying both the numerator and denominator of 3/4 by 3 gives 9/12.
13. Question 13 — Correct Answer: C. 0.333… Dividing 1 by 3 gives 0.333…, a non-terminating recurring decimal.
14. Question 14 — Correct Answer: D. Their decimal expansions are non-terminating and non-recurring. Irrational numbers have decimal expansions that neither terminate nor repeat in a recurring pattern.
15. Question 15 — Correct Answer: B. 5/8 1/2 = 4/8 and 3/4 = 6/8. Since 4/8 < 5/8 < 6/8, the correct answer is 5/8.

NEED MORE PRACTICE?

Get 50 Solved MCQs!

Class 9 Maths · Chapter 3

• Practise additional multiple-choice questions.
• Test your understanding of the chapter.
• Use the included answer key to check your work.
• Download and practise with the worksheet PDF.