9th Maths 1.1

NCERT Class 9th solution of Exercise 1.2

NCERT Class 9th solution of Exercise 1.3

NCERT Class 9th solution of Exercise 1.4

NCERT Class 9th solution of Exercise 1.5

NCERT Class 9th solution of Exercise 1.6

NCERT Class 9th Maths Projects

Exercise 1.1

Q1. Is zero a rational number? Can you write it in the form of `frac{p}{q}`: where p and q are integers and q≠0. 
Ans. :

Yes, 

`0` =`frac{0}{1}`=`frac{0}{2}`= `frac{0}{3}` etc.,

denominator q can also be taken as a negative integer.

Q2. Find six rational numbers between 3 and 4.
Sol. 

The denominator of these rational number will 6+1 = 7,

We can write given numbers 3 and 4 in `frac{p}{q}` form where q ≠ 0.

`frac{3×7}{1×7}` =`frac{21}{7}` 

and

`frac{4×7}{1×7}` = `frac{28}{7}`

So that required 6 rational numbers are:

`frac{22}{7}`, `frac{23}{7}`, `frac{24}{7}`, `frac{25}{7}`, `frac{26}{7}`, `frac{27}{7}`

Answer :

`frac{22}{7}`, `frac{23}{7}`, `frac{24}{7}`, `frac{25}{7}`, `frac{26}{7}`, `frac{27}{7}`

Q3. Find five rational  numbers between `frac{3}{5}` and `frac{4}{5}`
Sol: 

We find five rational number between `frac{3}{5}` and `frac{4}{5}` 

So we multiply numerator and denominator by (5+1) = 6

`frac{3×6}{5×6}` = `frac{18}{30}` 

and 

`frac{4×6}{5×6}` = `frac{20}{30}`

So that required 5 rational numbers are:

`frac{19}{30}`, `frac{20}{30}`, `frac{21}{30}`, `frac{22}{30}`, `frac{23}{30}`

Answer :

`frac{19}{30}`, `frac{20}{30}`, `frac{21}{30}`, `frac{22}{30}`, `frac{23}{30}`

Q4. State whether the following statements are true or false. Give reasons for your answer :

(i) Every natural number is a whole number.

Answer :

True, since the collection of whole numbers contains all the natural numbers.

(ii) Every integer is a whole number.

Answer :

False, for example, -2 is not a whole number. 

(iii) Every rational number is a whole number.

Answer :

False, for example, `frac{1}{2}` is a rational number but not a whole number.