# Class 9 Maths Chapter 1 Number System MCQs

Class 9 Maths Chapter 1 Number System MCQs are available here with solutions.  The MCQs are prepared as per the CBSE syllabus (2021-2022) and NCERT curriculum. These objective questions are given online,  as per the latest exam pattern. Also, we have provided detailed explanations for some questions to help students understand the concept very well. Solving the chapter-wise MCQs for 9th Standard Maths subject will help students to boost their problem-solving skills and confidence. Also, check Important Questions for Class 9 Maths here.

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## MCQs on Class 9 Maths Chapter 1 Number System

Check the below multiple choice questions for 9th Class Maths chapter 1-Number system. All MCQs have four options, out of which only one is correct. Students have to choose the correct option and check the answer with the provided one.

1.) Can we write 0 in the form of p/q?

a. Yes

b. No

c. Cannot be explained

d. None of the above

Explanation: 0 is a rational number and hence it can be written in the form of p/q.

Example: 0/4 = 0

2.) The three rational numbers between 3 and 4 are:

a. 5/2, 6/2, 7/2

b. 13/4, 14/4, 15/4

c. 12/7, 13/7, 14/7

d.11/4, 12/4, 13/4

Explanation: There are many rational numbers between 3 and 4

To find 3 rational numbers, we need to multiply and divide both the numbers by 3+1 = 4

Hence, 3 x (4/4) = 12/4 and 4 x (4/4) = 16/4

Thus, three rational numbers between 12/4 and 16/4 are 13/4, 14/4 and 15/4.

3.) In between any two numbers, there are:

a. Only one rational number

b. Two rational numbers

c. Infinite rational numbers

d. No rational number

Explanation: Take the reference from question number 2 explained above.

4.) Every rational number is:

a. Whole number

b. Natural number

c. Integer

d. Real number

5.) √9 is  __________ number.

a. A rational

b. An irrational

c. Neither rational nor irrational

d. None of the above

Explanation: √9 = 3

Hence, √9 is a rational number.

6.) Which of the following is an irrational number?

a. √16

b. √(12/3)

c. √12

d. √100

Explanation: √12 cannot be simplified to a rational number.

7.) 3√6 + 4√6 is equal to:

a. 6√6

b. 7√6

c. 4√12

d. 7√12

Explanation: 3√6 + 4√6 = (3 + 4)√6 = 7√6

8.) √6 x √27 is equal to:

a. 9√2

b. 3√3

c. 2√2

d. 9√3

Explanation: √6 x √27 = √(6  x 27) = √(2 x 3 x 3 x 3 x 3) = (3 x 3)√2 = 9√2

9.) Which of the following is equal to x3?

a. x– x3

b. x6.x3

c. x6/x3

d. (x6)3

Explanation: x6/x3 = x6 – 3 = x3

10.) Which of the following is an irrational number?

a. √23

b. √225

c. 0.3796

d. 7.478478

Explanation: √23 = 4.79583152331…

Since the decimal expansion of the number is non-terminating non-recurring. Hence, it is an irrational number.

11.) Which of the following is an irrational number?

a. 0.14

b. $$0.14\overline{16}$$

c. $$0.\overline{1416}$$

d. 0.4014001400014…

Explanation: 0.4014001400014…is an irrational number as it is non-terminating and non-repeating.

12.) 2√3+√3 =

a. 6

b. 2√6

c. 3√3

d. 4√6

Explanation: 2√3+√3 = (2+1)√3= 3√3.

13.) Find the value of $$\sqrt{\frac{\sqrt{2}-1}{\sqrt{2}+1}}$$, if √2 = 1.4142.

a. 5.8282

b. 0.1718

c. 0.4142

d. 2.4142

Explanation:

$$\sqrt{\frac{\sqrt{2}-1}{\sqrt{2}+1}}$$ = $$\sqrt{\frac{1.4142-1}{1.4142+1}}$$

=$$\sqrt{\frac{0.4142}{2.4142}}$$

= 0.4142

14.) The number obtained on rationalising the denominator of $$\frac{1}{\sqrt{7}-2}$$ is

a. (√7+2)/3

b. (√7-2)/3

c. (√7+2)/5

d. (√7+2)/45

Explanation:

$$\frac{1}{\sqrt{7}-2} = \frac{1}{\sqrt{7}-2}\times \frac{\sqrt{7}+2}{\sqrt{7}+2} = \frac{\sqrt{7}+2}{(\sqrt{7})^{2}-(2)^{2}} = \frac{\sqrt{7}+2}{3}$$

15.) Which of the following is rational?

a. 4/0

b. 0/4

c. √3

d. π

Explanation: 0/4 is a rational number that is equal to 0. Whereas π and √3 are irrational numbers and 4/0 is meaningless.

16.) The irrational number between 2 and 2.5 is

a. √11

b. √5

c. √22.5

d. √12.5

Explanation: The irrational number between 2 and 2.5 is √5 because the approximate value of √5 is 2. 23606…

17.) The value of √10 times √15 is equal to

a. 5√6

b. √25

c. 10√5

d. √5

Explanation: √10×√15 =(√2.√5)×(√3. √5) = 5√6.

18.) The decimal representation of the rational number is

a. Always terminating

b. Either terminating or repeating

c. Either terminating or non-repeating

d. Neither terminating nor repeating

Explanation: As per the definition of rational number, its decimal representation is either terminating or repeating.

19.) Which of the following is a rational number?

a. 0

b. 2√3

c. 2+√3

d. π

Explanation: 0 is a rational number, and it can be written as 0/1 or 0/2 or 0/3 etc. Whereas 2√3, 2+√3, and π are irrational numbers.

20.) Which of the following is an irrational number?

a. √(4/9)

b. √12/√3

c. √7

d. √81