R.D. Sharma Solutions Class 9th: Ch 1 Number System Exercise 1.2

Chapter 1 Number System R.D. Sharma Solutions for Class 9th Math Exercise 1.2

Exercise 1.2

1. Express the following rational numbers as decimals:
(i) 42/100
(ii) 327/500
(iii) 15/4

Solution

(i) Given rational number is 42/100
Now we have to express this rational number into decimal form. So we will use long division method as below.



Hence, 42/100 = 0.42

(ii) Given rational number is 327/500 
Now we have to express this rational number into decimal form. So we will use long division method as below. 
 
Hence,  327/100 = 0.654 

(iii) Given rational number is 15/4
Now we have to express this rational number into decimal form. So we will use long division method as below.
Hence, 15/4 = 3.75

2. Express the following rational numbers as decimals: 
(i) 2/3
(ii) -4/9
(iii) -2/15
(iv) -22/13
(v) 437/999
(vi) 33/26

Solution 

(i) Given rational number is 2/3  
Now we have to express this rational number into decimal form. So we will use long division method 


 (ii) Given rational number is -4/9
Now we have to express this rational number into decimal form. So we will use long division method


(iii) Given rational number is -2/15
Now we have to express this rational number into decimal form. So we will use long division method


(iv) Given rational number is -22/13
Now we have to express this rational number into decimal form. So we will use long division method


(v) Given rational number is 437/999
Now we have to express this rational number into decimal form. So we will use long division method



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

Solution

Prime factorization is the process of finding which prime numbers you need to multiply together to get a certain number. So prime factorization of denominators (q) must have only the power of 2 or 5 or both.

Watch age fraud in sports in India

GET OUR ANDROID APP

Get Offline Ncert Books, Ebooks and Videos Ask your doubts from our experts Get Ebooks for every chapter Play quiz while you study

Download our app for FREE

Study Rankers Android App Learn more

Study Rankers App Promo