#### 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)Â Given rational number is 327/500Â

Now we have to express this rational number into decimal form. So we will use long division method as below.Â

Â

Hence,Â 327/100 = 0.654Â

(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:Â

(i) 2/3

(ii) -4/9

(iii) -2/15

(iv) -22/13

(v) 437/999

(vi) 33/26

**Solution**Â

(i) Given rational number is 2/3Â Â

Now we have to express this rational number into decimal form. So we will use long division methodÂ

Â (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 â‰ 0),p/q (q â‰ 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.