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# RD Sharma Solutions Ex-1.2, Number System, Class 9, Maths Class 9 Notes | EduRev

## RD Sharma Solutions for Class 9 Mathematics

Created by: Abhishek Kapoor

## Class 9 : RD Sharma Solutions Ex-1.2, Number System, Class 9, Maths Class 9 Notes | EduRev

The document RD Sharma Solutions Ex-1.2, Number System, Class 9, Maths Class 9 Notes | EduRev is a part of the Class 9 Course RD Sharma Solutions for Class 9 Mathematics.
All you need of Class 9 at this link: Class 9

Q1. Express the following rational numbers as decimals:

(i) 42/100

(ii) 327/500

(iii) 15/4

Solution:

(i) By long division method

100) ( 0.42

400 200 Therefore,  42/100 = 0.42

(ii) By long division method 3000 2500 2000 Therefore, 327/500 = 0.654

(iii) By long division method 12 28 20 Therefore, 15/4 = 3.75

Q2. Express the following rational numbers as decimals:

(i) 2/3

(ii)   (v) 437/999

Solution:

(i) By long division method 18 18 Therefore, 2/3 = 0.66

(ii) By long division method 3600 3600 3600 Therefore, – 0.444

(iii) By long division method 15 45 45 45 Therefore, 2/15 = -1.333

(iv) By long division method 13 78 117 26 39 91 78 117 Therefore, = – 1.69230769

(v) By long division method 3996 2997 6993 3996 2997 Therefore, 437/999 = 0.43743

Q3. Look at several examples of rational numbers in the form of p/q (q ≠ 0), where p and q are integers with no common factor other than 1 and having terminating decimal representations. Can you guess what property q must satisfy?

Solution: A rational number p/q is a terminating decimal only, when prime factors of q are q and 5 only. Therefore, p/q  is a terminating decimal only, when prime factorization of q must have only powers of 2 or 5 or both.

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