#### Class Nine Chapter 1 NCERT Solutions

#### CLASS 9 CHAPTER 1: NUMBER SYSTEMS

Exercise 1.1 Part 1

**1. **Is zero a rational number? Can you write it in the form p/q

where p and q are integers and q ≠ 0?

Sol. Yes, zero is a rational number. It can be written as

where p and q are
integers

and q ≠ 0.

- Find
six rational numbers between 3 and 4.

Sol. To find six rational numbers between 3 and 4, the denominator should be made equal to 6 + 1 = 7

#### Class Nine Chapter 1 NCERT Solutions

Six rational numbers between 3 and 4 can be found by varying the numerators between 21 and 28. Or, the numbers are

- Find five rational numbers between 3/5 and 4/5

Sol. To find five rational numbers between 3/5 and 4/5

we may add the given numbers and divide by 2, and repeat the process.

Many answers are possible to this question. There are of course infinitely many rational numbers between 3/5 and 4/5.

4. State whether the following statements are true or false. Give reasons for your answers.

(i) Every natural number is a whole number.

(ii) Every integer is a whole number.

(iii) Every rational number is a whole number.

Sol. (i) True. Since the collection of whole numbers contains all the natural numbers.

(ii) False. Negative integers are not whole numbers.