Scroll:Real Number System >> Rational Numbers ( Exercise 1.1) >> saq (4363)


Written Instructions:

For each Multiple Choice Question (MCQ), four options are given. One of them is the correct answer. Make your choice (1,2,3 or 4). Write your answers in the brackets provided..

For each Short Answer Question(SAQ) and Long Answer Question(LAQ), write your answers in the blanks provided.

Leave your answers in the simplest form or correct to two decimal places.



 

1)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

24 , 25 and -38

RHS =


Answer:_______________




2)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

24 , 26 and -46

RHS =


Answer:_______________




3)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

12 , 34 and -47

RHS =


Answer:_______________




4)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

23 , 26 and -36

RHS =


Answer:_______________




5)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

12 , 34 and -38

RHS =


Answer:_______________




6)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

33 , 36 and -38

RHS =


Answer:_______________




7)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

34 , 25 and -37

RHS =


Answer:_______________




8)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

23 , 56 and -25

RHS =


Answer:_______________




9)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

33 , 24 and -37

RHS =


Answer:_______________




10)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

23 , 25 and -47

RHS =


Answer:_______________




 

1)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

24 , 25 and -38

RHS = Answer: 2140


SOLUTION 1 :

To verify,

( 24 + 25 ) + ( -38 )  =   24 + ( 25 + ( -38 )

LHS

2
+
 
2
+
 
-3 = 2x5 + 2x4 + -3
4 5 8 4x5 5x4 8

 

[ LCM of 4 and 5 is 20]

 

10
+
 
8 + -3
20 20 8

 

10+8
+
 
-3  = 18 -3 18 3
20  8 20 8 20 8

 

[LCM of 20 ans 8 is 160]

18x8
-
 
3x20 = 144 - 60 = 144- 60 = 84 = 2140
20x8 8x20 160 160 160 160

 

LHS = 2140

 

RHS   24 + ( 25 + ( -38 )  =   24 + ( 25 -38 )

2
+
 
2x8 - 3x5
4 5x8 8x5

 

[LCM of 5 and 8 is 40]

2
+
 
16 - 15 = 2

+

16-15 = 2 + 1
4 40 40 4 40 4 40

 

[LCM of 4 and 40 is 160]

 

2x40
+
 
1x4 = 80 + 4 = 80+(4) = 84 = 2140
4x40 40x4 160 160 160 160

 

RHS = 2140

LHS = RHS

Hence, associative property is true for addition.



2)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

24 , 26 and -46

RHS = Answer: 16


SOLUTION 1 :

To verify,

( 24 + 26 ) + ( -46 )  =   24 + ( 26 + ( -46 )

LHS

2
+
 
2
+
 
-4 = 2x6 + 2x4 + -4
4 6 6 4x6 6x4 6

 

[ LCM of 4 and 6 is 24]

 

12
+
 
8 + -4
24 24 6

 

12+8
+
 
-4  = 20 -4 20 4
24  6 24 6 24 6

 

[LCM of 24 ans 6 is 144]

20x6
-
 
4x24 = 120 - 96 = 120- 96 = 24 = 16
24x6 6x24 144 144 144 144

 

LHS = 16

 

RHS   24 + ( 26 + ( -46 )  =   24 + ( 26 -46 )

2
+
 
2x6 - 4x6
4 6x6 6x6

 

[LCM of 6 and 6 is 36]

2
+
 
12 - 24 = 2

+

12-24 = 2 + -12
4 36 36 4 36 4 36

 

[LCM of 4 and 36 is 144]

 

2x36
+
 
-12x4 = 72 + -48 = 72+(-48) = 24 = 16
4x36 36x4 144 144 144 144

 

RHS = 16

LHS = RHS

Hence, associative property is true for addition.



3)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

12 , 34 and -47

RHS = Answer: 1928


SOLUTION 1 :

To verify,

( 12 + 34 ) + ( -47 )  =   12 + ( 34 + ( -47 )

LHS

1
+
 
3
+
 
-4 = 1x4 + 3x2 + -4
2 4 7 2x4 4x2 7

 

[ LCM of 2 and 4 is 8]

 

4
+
 
6 + -4
8 8 7

 

4+6
+
 
-4  = 10 -4 10 4
7 8 7 8 7

 

[LCM of 8 ans 7 is 56]

10x7
-
 
4x8 = 70 - 32 = 70- 32 = 38 = 1928
8x7 7x8 56 56 56 56

 

LHS = 1928

 

RHS   12 + ( 34 + ( -47 )  =   12 + ( 34 -47 )

1
+
 
3x7 - 4x4
2 4x7 7x4

 

[LCM of 4 and 7 is 28]

1
+
 
21 - 16 = 1

+

21-16 = 1 + 5
2 28 28 2 28 2 28

 

[LCM of 2 and 28 is 56]

 

1x28
+
 
5x2 = 28 + 10 = 28+(10) = 38 = 1928
2x28 28x2 56 56 56 56

 

RHS = 1928

LHS = RHS

Hence, associative property is true for addition.



4)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

23 , 26 and -36

RHS = Answer: 12


SOLUTION 1 :

To verify,

( 23 + 26 ) + ( -36 )  =   23 + ( 26 + ( -36 )

LHS

2
+
 
2
+
 
-3 = 2x6 + 2x3 + -3
3 6 6 3x6 6x3 6

 

[ LCM of 3 and 6 is 18]

 

12
+
 
6 + -3
18 18 6

 

12+6
+
 
-3  = 18 -3 18 3
18  6 18 6 18 6

 

[LCM of 18 ans 6 is 108]

18x6
-
 
3x18 = 108 - 54 = 108- 54 = 54 = 12
18x6 6x18 108 108 108 108

 

LHS = 12

 

RHS   23 + ( 26 + ( -36 )  =   23 + ( 26 -36 )

2
+
 
2x6 - 3x6
3 6x6 6x6

 

[LCM of 6 and 6 is 36]

2
+
 
12 - 18 = 2

+

12-18 = 2 + -6
3 36 36 3 36 3 36

 

[LCM of 3 and 36 is 108]

 

2x36
+
 
-6x3 = 72 + -18 = 72+(-18) = 54 = 12
3x36 36x3 108 108 108 108

 

RHS = 12

LHS = RHS

Hence, associative property is true for addition.



5)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

12 , 34 and -38

RHS = Answer: 78


SOLUTION 1 :

To verify,

( 12 + 34 ) + ( -38 )  =   12 + ( 34 + ( -38 )

LHS

1
+
 
3
+
 
-3 = 1x4 + 3x2 + -3
2 4 8 2x4 4x2 8

 

[ LCM of 2 and 4 is 8]

 

4
+
 
6 + -3
8 8 8

 

4+6
+
 
-3  = 10 -3 10 3
8 8 8 8 8

 

[LCM of 8 ans 8 is 64]

10x8
-
 
3x8 = 80 - 24 = 80- 24 = 56 = 78
8x8 8x8 64 64 64 64

 

LHS = 78

 

RHS   12 + ( 34 + ( -38 )  =   12 + ( 34 -38 )

1
+
 
3x8 - 3x4
2 4x8 8x4

 

[LCM of 4 and 8 is 32]

1
+
 
24 - 12 = 1

+

24-12 = 1 + 12
2 32 32 2 32 2 32

 

[LCM of 2 and 32 is 64]

 

1x32
+
 
12x2 = 32 + 24 = 32+(24) = 56 = 78
2x32 32x2 64 64 64 64

 

RHS = 78

LHS = RHS

Hence, associative property is true for addition.



6)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

33 , 36 and -38

RHS = Answer: 98


SOLUTION 1 :

To verify,

( 33 + 36 ) + ( -38 )  =   33 + ( 36 + ( -38 )

LHS

3
+
 
3
+
 
-3 = 3x6 + 3x3 + -3
3 6 8 3x6 6x3 8

 

[ LCM of 3 and 6 is 18]

 

18
+
 
9 + -3
18 18 8

 

18+9
+
 
-3  = 27 -3 27 3
18  8 18 8 18 8

 

[LCM of 18 ans 8 is 144]

27x8
-
 
3x18 = 216 - 54 = 216- 54 = 162 = 98
18x8 8x18 144 144 144 144

 

LHS = 98

 

RHS   33 + ( 36 + ( -38 )  =   33 + ( 36 -38 )

3
+
 
3x8 - 3x6
3 6x8 8x6

 

[LCM of 6 and 8 is 48]

3
+
 
24 - 18 = 3

+

24-18 = 3 + 6
3 48 48 3 48 3 48

 

[LCM of 3 and 48 is 144]

 

3x48
+
 
6x3 = 144 + 18 = 144+(18) = 162 = 98
3x48 48x3 144 144 144 144

 

RHS = 98

LHS = RHS

Hence, associative property is true for addition.



7)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

34 , 25 and -37

RHS = Answer: 101140


SOLUTION 1 :

To verify,

( 34 + 25 ) + ( -37 )  =   34 + ( 25 + ( -37 )

LHS

3
+
 
2
+
 
-3 = 3x5 + 2x4 + -3
4 5 7 4x5 5x4 7

 

[ LCM of 4 and 5 is 20]

 

15
+
 
8 + -3
20 20 7

 

15+8
+
 
-3  = 23 -3 23 3
20  7 20 7 20 7

 

[LCM of 20 ans 7 is 140]

23x7
-
 
3x20 = 161 - 60 = 161- 60 = 101 = 101140
20x7 7x20 140 140 140 140

 

LHS = 101140

 

RHS   34 + ( 25 + ( -37 )  =   34 + ( 25 -37 )

3
+
 
2x7 - 3x5
4 5x7 7x5

 

[LCM of 5 and 7 is 35]

3
+
 
14 - 15 = 3

+

14-15 = 3 + -1
4 35 35 4 35 4 35

 

[LCM of 4 and 35 is 140]

 

3x35
+
 
-1x4 = 105 + -4 = 105+(-4) = 101 = 101140
4x35 35x4 140 140 140 140

 

RHS = 101140

LHS = RHS

Hence, associative property is true for addition.



8)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

23 , 56 and -25

RHS = Answer: 1110


SOLUTION 1 :

To verify,

( 23 + 56 ) + ( -25 )  =   23 + ( 56 + ( -25 )

LHS

2
+
 
5
+
 
-2 = 2x6 + 5x3 + -2
3 6 5 3x6 6x3 5

 

[ LCM of 3 and 6 is 18]

 

12
+
 
15 + -2
18 18 5

 

12+15
+
 
-2  = 27 -2 27 2
18  5 18 5 18 5

 

[LCM of 18 ans 5 is 90]

27x5
-
 
2x18 = 135 - 36 = 135- 36 = 99 = 1110
18x5 5x18 90 90 90 90

 

LHS = 1110

 

RHS   23 + ( 56 + ( -25 )  =   23 + ( 56 -25 )

2
+
 
5x5 - 2x6
3 6x5 5x6

 

[LCM of 6 and 5 is 30]

2
+
 
25 - 12 = 2

+

25-12 = 2 + 13
3 30 30 3 30 3 30

 

[LCM of 3 and 30 is 90]

 

2x30
+
 
13x3 = 60 + 39 = 60+(39) = 99 = 1110
3x30 30x3 90 90 90 90

 

RHS = 1110

LHS = RHS

Hence, associative property is true for addition.



9)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

33 , 24 and -37

RHS = Answer: 1514


SOLUTION 1 :

To verify,

( 33 + 24 ) + ( -37 )  =   33 + ( 24 + ( -37 )

LHS

3
+
 
2
+
 
-3 = 3x4 + 2x3 + -3
3 4 7 3x4 4x3 7

 

[ LCM of 3 and 4 is 12]

 

12
+
 
6 + -3
12 12 7

 

12+6
+
 
-3  = 18 -3 18 3
12  7 12 7 12 7

 

[LCM of 12 ans 7 is 84]

18x7
-
 
3x12 = 126 - 36 = 126- 36 = 90 = 1514
12x7 7x12 84 84 84 84

 

LHS = 1514

 

RHS   33 + ( 24 + ( -37 )  =   33 + ( 24 -37 )

3
+
 
2x7 - 3x4
3 4x7 7x4

 

[LCM of 4 and 7 is 28]

3
+
 
14 - 12 = 3

+

14-12 = 3 + 2
3 28 28 3 28 3 28

 

[LCM of 3 and 28 is 84]

 

3x28
+
 
2x3 = 84 + 6 = 84+(6) = 90 = 1514
3x28 28x3 84 84 84 84

 

RHS = 1514

LHS = RHS

Hence, associative property is true for addition.



10)  

 Verify whether associative property is satisfied for addition of the following pairs of rational numbers.(ples use /)

23 , 25 and -47

RHS = Answer: 52105


SOLUTION 1 :

To verify,

( 23 + 25 ) + ( -47 )  =   23 + ( 25 + ( -47 )

LHS

2
+
 
2
+
 
-4 = 2x5 + 2x3 + -4
3 5 7 3x5 5x3 7

 

[ LCM of 3 and 5 is 15]

 

10
+
 
6 + -4
15 15 7

 

10+6
+
 
-4  = 16 -4 16 4
15  7 15 7 15 7

 

[LCM of 15 ans 7 is 105]

16x7
-
 
4x15 = 112 - 60 = 112- 60 = 52 = 52105
15x7 7x15 105 105 105 105

 

LHS = 52105

 

RHS   23 + ( 25 + ( -47 )  =   23 + ( 25 -47 )

2
+
 
2x7 - 4x5
3 5x7 7x5

 

[LCM of 5 and 7 is 35]

2
+
 
14 - 20 = 2

+

14-20 = 2 + -6
3 35 35 3 35 3 35

 

[LCM of 3 and 35 is 105]

 

2x35
+
 
-6x3 = 70 + -18 = 70+(-18) = 52 = 52105
3x35 35x3 105 105 105 105

 

RHS = 52105

LHS = RHS

Hence, associative property is true for addition.