NCERT Solutions for Class 9 Maths Chapter 1

Download NCERT Solutions for Class 9 Maths Chapter 1 Exercise 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 of Number Systems in English Medium and Hindi Medium to use online free. NCERT Solutions for Class 9 Maths all chapters solutions in PDF form is also available. Here you have choice to use solutions of chapter 1 number system as online.

NCERT Solutions for Class 9 Maths Chapter 1

If you need solutions in Hindi, Click for Hindi Medium solutions of 9 Maths Chapter 1         9 Maths Solutions: Main Page

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9 Maths Chapter 1 All Exercises in Hindi         9 Maths Solutions: Main Page

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Important Questions – Number Systems
1. Write first five whole numbers in p/q form. Where p and q are integers and q ≠ 0. [Answer: 0/1, 1/1, 2/1, 3/1, 4/1]
2. Find decimal expansion of 17/8, 3/15, 2/7, 50/3. [Answer: 17/8 = 2.125, 3/15 = 0.2, 2/7 = 0.285714285714…, 50/3 = 16.6666…]
3. Find four rational numbers between 2/9 and 3/7. [Answer: 15/63, 16/63, 17/63, 18/63]
4. Find decimal form of √23 and √24 upto 3 decimal places. [Answer: √23 = 4.795 and √24 = 4.898]
5. Find one Irrational and one rational number between 2 and √5. [Answer: 2.12, 2.010010001…]
6. Write two numbers whose decimal expansions are terminating. [Answer: 7/5, 7/2]
7. What can be the maximum number of digits in the repeating block of digits in the decimal expansion of 5/7? [Answer: 6]
8. Write two numbers whose decimal expansions are non-terminating non-repeating (non-recurring). [Answer: √2, √3]
9. Find two Irrational numbers between 2017 and 2018. [Answer: 2017.101001000…, 2017.202002000…]
10. Representation – 7/5 on the number line.
11. Represent √5 on the number line.
12. Represent 3 + √2.6 on the number line.
13. Insert two Irrational numbers between 2/3 and 3/2. [Answer: 0.909009000…, 1.101001000…]
14. Which of the following rational numbers will have a terminating decimal expansion or a non-terminating repeating (recurring) decimal expansion? (i) 135/50 (ii) 4/11 (iii) 8/7
15. Classify the following numbers as terminating decimal or non-terminating recurring decimal or non-terminating non-recurring decimal: (i) 0.1666…. (ii) 0.250 ……. (iii) 1.01001000100001…. (iv) 0.27696 (v) 2.142857142857…. (vi) 0.3 (vii) 0.2359872785…. Classify these given numbers also as Rational or Irrational numbers. [Answer: (i) Terminating Decimal (ii) Non Terminating Repeating Decimal. (iii) Non-Terminating Repeating Decimal (iv) Terminating Decimal (v) Non-Terminating Repeating Decimal, (vi) Terminating Decimal (vii) Terminating Decimal]
16. Express the following numbers in the form p/q, where p and q are integers and q ≠ 0. (i) 0.0875 (ii) 2.123456789 (iii) 0.181818…. (iv) 0.437373737… (v) 3.6511111….
17. If x = 9 – 4√5, then find (i) x + 1/x (ii) x² + 1/x²
18. Every rational number is
(A) a natural number (B) an integer (C) a real number (D) a whole number [Answer: D]
19. Decimal representation of a rational number cannot be
(A) terminating (B) non-terminating (C) non-terminating repeating (D) non-terminating non-repeating [Answer: D]
20. The product of any two irrational numbers is
(A) always an irrational number (B) always a rational number (C) always an integer (D) sometimes rational numbers, sometimes irrational [Answer: D]
21. Let x and y be rational and irrational numbers, respectively. Is x + y necessarily an irrational number? Give an example in support of your answer.
22. Show that 0.142857142857… = 1/7