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# S.chand books class 8 maths solution chapter 1 Rational Numbers exercise 1 A

## Exercise 1 A

#### Question 1

Fill in the blanks

(i) , expressed as a rational number with denominator

Sol :

Denominator can not be negative

On dividing and multiplying by 6

(ii) (>,<,=)

Sol :

L.C.M of 7 and 11 is 77

..(i)

Denominator can not be negative

..(ii)

From (i) and (ii)

(iii) The absolute value of

Sol :

(iv) The rational numbers whose absolute value is are __ .

Sol :

(v) The rational number which is neither positive nor negative is ___ .

Sol :

0

#### Question 2

Answer True (T) or False (F)

(i) Every rational number is a whole number.

Sol : F

(ii) 0 is the smallest rational number .

Sol : F

(iii) Every fractional number is a rational number.

Sol : T

(iv) is a rational number .

Sol : F

(v) |x| = -x , if x<0

Sol : T

#### Question 3

Write four rational numbers equivalent to each of the following rational numbers

NOTE: Equivalent rational numbers can be find by multiplying or dividing by same number to rational numbers

(i)

Sol :

..(i)

..(ii)

..(iii)

..(iv)

(ii)

Sol :

..(i)

..(ii)

..(iii)

..(iv)

(iii)

Sol :

..(i)

..(ii)

..(iii)

..(iv)

(iv)

Sol :

..(i)

..(ii)

..(iii)

..(iv)

#### Question 4

Which of the two rational numbers is greater?

(i)

Sol :

(ii)

Sol :

L.C.M of 16 and 8 is 16

..(i)

..(ii)

From (i) and (ii)

(iii)

Sol :

(iv)

Sol :

Denominator can’t be negative

L.C.M of 3 and 13 is 39

..(i)

..(ii)

From (i) and (ii)

#### Question 5

Which of the two rational numbers is smaller?

NOTE: To compare two rational numbers , we compare their cross product

⇒p×s and r×q

(i) if p×s > r×q , then

(ii) if p×s < r×q, then

(i)

Sol :

(ii)

Sol :

(iii)

Sol :

(iv)

Sol :

..(i)

Denominator can not be negative

..(ii)

From (i) and (ii)

Cross multiplication

⇒-103 < -101

⇒⇒

#### Question 6

Which of the symbols = , <  or > should replace the blank space ?

(i)

Sol : >

(ii)

Sol : >

L.C.M of 2 and 5 is 10

..(i)

..(ii)

From (i) and (ii)

(iii)

Sol : <

L.C.M of 4 and 3 is 12

..(i)

..(ii)

From (i) and (ii)

(iv)

Sol : >

L.C.M of 7 and 5 is 35

..(i)

..(ii)

From (i) and (ii)

(v)

Sol : <

L.C.M of 7 and 9 is 63

..(i)

..(ii)

From (i) and (ii)

(vi)

Sol : <

L.C.M of 3 and 7 is 21

..(i)

Denominator can not be negative

..(ii)

From (i) and (ii)

(vii)

Sol : >

L.C.M of 15 and 11 is 165

Denominator can not be negative

..(i)

And

..(ii)

From(i) and (ii)

(viii)

Sol : <

[negative sign cancelled out]

#### Question 7

Arrange in order from least to greatest

(i)

Sol :

L.C.M of 4 , 8 and 7 is 56

..(i)

..(ii)

..(iii)

From (i) , (ii) and (iii)

or

(ii)

Sol :

L.C.M of 5 , 2 and 11 is 110

..(i)

..(ii)

..(iii)

From (i) , (ii) and (iii)

or

(iii)

Sol :

L.C.M of 5 , 10 and 3 is 30

..(i)

..(ii)

..(iii)

From (i) , (ii) and (iii)

or

#### Question 8

Arrange in descending order .

(i)

Sol :

L.C.M of 4 , 7 , 14 and 8 is 56

..(i)

..(ii)

..(iii)

..(iv)

From (i) , (ii) , (iii) and (iv)

or

(ii)

Sol :

L.C.M of 11 , 3 and 12 is 132

..(i)

..(ii)

..(iii)

From (i) , (ii) and (iii)

or

(iii)

Sol :

L.C.M of 5 , 15 ,10 and 10 is 30

..(i)

..(ii)

..(iii)

..(iv)

From (i) , (ii) , (iii) and (iv)

or

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