NCERT Class 9 Solutions: Number Systems (Chapter 1) Exercise 1.1
Q.1 Is zero a rational number? Can you write it in the form where p and q are integers and ?
Solution:

Yes, zero is a rational number.

A rational number is a real number that can be written as a simple fraction.

In a fraction both the numerator and denominator are whole numbers.

Most numbers we use in everyday life are Rational Numbers.

Every whole numbers is a rational numbers, because any whole number can be written as a fraction.

For example It can write as etc
It’s all are form of , where p and q are integers and
Q.2 Find six rational numbers between 3 and 4
Solution:

Given 2 rational numbers are 3 and 4

To find six rational numbers between 3 and 4
Denominator should be made equal to
So multiply in numerator and denominator by 7 we get,
,
Six rational numbers between 3 and 4 can be found by varying the numerator between 21 and 28
We know that
So, the numbers are
Hence, six rational number between are:
Q.3 Find five rational numbers between .
Solution:

Given 2 rational numbers are

And to find five rational numbers between
Denominator should be made equal to
So multiply in numerator and denominator by 6 we get,
,
Five rational numbers between can be found by varying the numerator between and
We know that
Therefore, the numbers are
Hence, five rational number between are:
Q.4 State whether the following statements are true or false. Give reasons for your answers.

Every natural numbers is a whole number.

Every integer is a whole number.

Every rational number is a whole number.
Solution:

1^{st} statement is True, Since the all whole numbers contains all natural numbers and in additional zero

2^{nd} statement is false, because Integers include but, Whole numbers include
So, Negatives integers are not whole numbers.

3^{rd} statement is false, because Rational numbers include but, Whole numbers include
Therefore, numbers are rational number but not whole numbers.