# CBSE Class 9 Maths: Extra Questions - Chapter 1 - Number System (with Answers)

**CBSE Class 9 Maths **extra Questions for Chapter 1 - Number System (with Answers). These questions are NCERT based important for the preparation of the upcoming CBSE 9th Maths Exam 2020-21. Most of the questions given here are very simple and can be solved in less than 5 minutes. If someone is facing problems in solving these questions then more clarity of basic concepts is required. These extra questions from Class 9 Maths Chapter 1 - Number System are also expected to be asked in CBSE Class 9 Maths test.

CBSE Class 9 Maths Extra Questions from Chapter 1 - Number System (with Answers):

1: Simplify: [{(82 + 92)2}0]2 = ____

Answer: 1.

2: 2(2/3) x 2(1/3)

Answer: 2.

3: [2 + (3)1/2] [2 - (3)1/2] = ______

Answer: 1.

CBSE Class 9 Maths Syllabus 2020-2021 (Reduced) - Download in PDF

4: Let a > 0 be a real number and p and q be rational numbers. Then which of the following statement(s) is/are correct?

(i) ap . aq = ap + q

(ii) ap bp = (ab)p

(iii) (ap)q = apq

(iv) All of these

Answer: (iv) All of these.

5: Find the value of 1/(4)3 ÷ 1/(4)3 + 1/(1)3

Answer: 2.

6: Divide 10 √15 by 5 √3 .

Answer: 2√5.

7. Which of the following given statement(s) is/are correct?

(i) The sum or difference of a rational number and an irrational number is irrational.

(ii) The product or quotient of a non-zero rational number with an irrational number is

irrational.

(iii) If we add, subtract, multiply or divide two irrationals, the result may be rational or

irrational

(iv) All of these statements are correct

Answer:

(iv) All of these statements are correct.

8. [1/(2 + √5)] can also be written as

(a) (2 - √5)

(b) (√5 - 2)

(c) [1/(2 ÷ √5)]

(d) [1 + (2 + √5)]

Answer:

[1/(2 + √5)] can be rationalised and can be written as (√5 - 2).

9. π (Pi) is a rational number or irrational number?

Answer:

π (Pi) is an irrational number.

10. The value of π = 22/7. 22/7 is a rational number then how come π is an irrational number?

Answer:

It is true that 22/7 is a rational number but π is irrational. Please note that 22/7 is an approximate value of π.

**NCERT Solutions for Class 9 Maths: Download all chapters in PDF**