Number System class 9 exercise 1.1

NCERT solution for MATHS class 9 NUMBER SYSTEM chapter 1 Exercise-1.1

  1. Is zero a rational number? Can you write it in the form p/q, where p and q are integers and q ≠ 0?


Earlier, We know that a number is said to be rational if it can be written in the form p/q, where p and q are integers and q ≠ 0.

Taking the case of ‘0’,

similarly, Zero can be written in the form 0/1, 0/2, 0/3 …

Then, it satisfies the necessary condition, we can conclude that the number (zero) 0 can be written in the p/q form, where q can either be a positive or negative number.

Hence, 0 is a rational number.

2. In short find six rational numbers between 3 and 4.



3. In short find five rational numbers between 3/5 and 4/5.


Trick: if we need to find ‘n’ numbers between ‘x’ and ‘y’ then multiply the numerator and denominator by (n+1).

Hence, According to the given question we need to find 5 numbers between 3/5 and 4/5. so multiply by ‘5+1=6’ in numerator and denominator.


five rational numbers between 3/5 and 4/5 are:


4. State whether the following statements are true or false. Also, 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.


i) True
∵ The collection of all natural numbers and 0 is called whole numbers.
(ii) False
∵ Negative integers are not whole numbers.
(iii) False
∵ Rational numbers are of the form p/q, q ≠ 0 and q does not divide p completely that are not whole numbers.

Click here, to begin with, a video solution to these questions.