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 /)

13 , 25 and -28

RHS =


Answer:_______________




2)  

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

23 , 55 and -48

RHS =


Answer:_______________




3)  

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

34 , 45 and -25

RHS =


Answer:_______________




4)  

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

13 , 46 and -45

RHS =


Answer:_______________




5)  

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

23 , 34 and -36

RHS =


Answer:_______________




6)  

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

22 , 45 and -38

RHS =


Answer:_______________




7)  

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

23 , 26 and -38

RHS =


Answer:_______________




8)  

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

24 , 54 and -25

RHS =


Answer:_______________




9)  

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

32 , 36 and -35

RHS =


Answer:_______________




10)  

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

24 , 35 and -47

RHS =


Answer:_______________




 

1)  

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

13 , 25 and -28

RHS = Answer: 2960


SOLUTION 1 :

To verify,

( 13 + 25 ) + ( -28 )  =   13 + ( 25 + ( -28 )

LHS

1
+
 
2
+
 
-2 = 1x5 + 2x3 + -2
3 5 8 3x5 5x3 8

 

[ LCM of 3 and 5 is 15]

 

5
+
 
6 + -2
15 15 8

 

5+6
+
 
-2  = 11 -2 11 2
15  8 15 8 15 8

 

[LCM of 15 ans 8 is 120]

11x8
-
 
2x15 = 88 - 30 = 88- 30 = 58 = 2960
15x8 8x15 120 120 120 120

 

LHS = 2960

 

RHS   13 + ( 25 + ( -28 )  =   13 + ( 25 -28 )

1
+
 
2x8 - 2x5
3 5x8 8x5

 

[LCM of 5 and 8 is 40]

1
+
 
16 - 10 = 1

+

16-10 = 1 + 6
3 40 40 3 40 3 40

 

[LCM of 3 and 40 is 120]

 

1x40
+
 
6x3 = 40 + 18 = 40+(18) = 58 = 2960
3x40 40x3 120 120 120 120

 

RHS = 2960

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 /)

23 , 55 and -48

RHS = Answer: 76


SOLUTION 1 :

To verify,

( 23 + 55 ) + ( -48 )  =   23 + ( 55 + ( -48 )

LHS

2
+
 
5
+
 
-4 = 2x5 + 5x3 + -4
3 5 8 3x5 5x3 8

 

[ LCM of 3 and 5 is 15]

 

10
+
 
15 + -4
15 15 8

 

10+15
+
 
-4  = 25 -4 25 4
15  8 15 8 15 8

 

[LCM of 15 ans 8 is 120]

25x8
-
 
4x15 = 200 - 60 = 200- 60 = 140 = 76
15x8 8x15 120 120 120 120

 

LHS = 76

 

RHS   23 + ( 55 + ( -48 )  =   23 + ( 55 -48 )

2
+
 
5x8 - 4x5
3 5x8 8x5

 

[LCM of 5 and 8 is 40]

2
+
 
40 - 20 = 2

+

40-20 = 2 + 20
3 40 40 3 40 3 40

 

[LCM of 3 and 40 is 120]

 

2x40
+
 
20x3 = 80 + 60 = 80+(60) = 140 = 76
3x40 40x3 120 120 120 120

 

RHS = 76

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 /)

34 , 45 and -25

RHS = Answer: 2320


SOLUTION 1 :

To verify,

( 34 + 45 ) + ( -25 )  =   34 + ( 45 + ( -25 )

LHS

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

 

[ LCM of 4 and 5 is 20]

 

15
+
 
16 + -2
20 20 5

 

15+16
+
 
-2  = 31 -2 31 2
20  5 20 5 20 5

 

[LCM of 20 ans 5 is 100]

31x5
-
 
2x20 = 155 - 40 = 155- 40 = 115 = 2320
20x5 5x20 100 100 100 100

 

LHS = 2320

 

RHS   34 + ( 45 + ( -25 )  =   34 + ( 45 -25 )

3
+
 
4x5 - 2x5
4 5x5 5x5

 

[LCM of 5 and 5 is 25]

3
+
 
20 - 10 = 3

+

20-10 = 3 + 10
4 25 25 4 25 4 25

 

[LCM of 4 and 25 is 100]

 

3x25
+
 
10x4 = 75 + 40 = 75+(40) = 115 = 2320
4x25 25x4 100 100 100 100

 

RHS = 2320

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 /)

13 , 46 and -45

RHS = Answer: 15


SOLUTION 1 :

To verify,

( 13 + 46 ) + ( -45 )  =   13 + ( 46 + ( -45 )

LHS

1
+
 
4
+
 
-4 = 1x6 + 4x3 + -4
3 6 5 3x6 6x3 5

 

[ LCM of 3 and 6 is 18]

 

6
+
 
12 + -4
18 18 5

 

6+12
+
 
-4  = 18 -4 18 4
18  5 18 5 18 5

 

[LCM of 18 ans 5 is 90]

18x5
-
 
4x18 = 90 - 72 = 90- 72 = 18 = 15
18x5 5x18 90 90 90 90

 

LHS = 15

 

RHS   13 + ( 46 + ( -45 )  =   13 + ( 46 -45 )

1
+
 
4x5 - 4x6
3 6x5 5x6

 

[LCM of 6 and 5 is 30]

1
+
 
20 - 24 = 1

+

20-24 = 1 + -4
3 30 30 3 30 3 30

 

[LCM of 3 and 30 is 90]

 

1x30
+
 
-4x3 = 30 + -12 = 30+(-12) = 18 = 15
3x30 30x3 90 90 90 90

 

RHS = 15

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 /)

23 , 34 and -36

RHS = Answer: 1112


SOLUTION 1 :

To verify,

( 23 + 34 ) + ( -36 )  =   23 + ( 34 + ( -36 )

LHS

2
+
 
3
+
 
-3 = 2x4 + 3x3 + -3
3 4 6 3x4 4x3 6

 

[ LCM of 3 and 4 is 12]

 

8
+
 
9 + -3
12 12 6

 

8+9
+
 
-3  = 17 -3 17 3
12  6 12 6 12 6

 

[LCM of 12 ans 6 is 72]

17x6
-
 
3x12 = 102 - 36 = 102- 36 = 66 = 1112
12x6 6x12 72 72 72 72

 

LHS = 1112

 

RHS   23 + ( 34 + ( -36 )  =   23 + ( 34 -36 )

2
+
 
3x6 - 3x4
3 4x6 6x4

 

[LCM of 4 and 6 is 24]

2
+
 
18 - 12 = 2

+

18-12 = 2 + 6
3 24 24 3 24 3 24

 

[LCM of 3 and 24 is 72]

 

2x24
+
 
6x3 = 48 + 18 = 48+(18) = 66 = 1112
3x24 24x3 72 72 72 72

 

RHS = 1112

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 /)

22 , 45 and -38

RHS = Answer: 5740


SOLUTION 1 :

To verify,

( 22 + 45 ) + ( -38 )  =   22 + ( 45 + ( -38 )

LHS

2
+
 
4
+
 
-3 = 2x5 + 4x2 + -3
2 5 8 2x5 5x2 8

 

[ LCM of 2 and 5 is 10]

 

10
+
 
8 + -3
10 10 8

 

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

 

[LCM of 10 ans 8 is 80]

18x8
-
 
3x10 = 144 - 30 = 144- 30 = 114 = 5740
10x8 8x10 80 80 80 80

 

LHS = 5740

 

RHS   22 + ( 45 + ( -38 )  =   22 + ( 45 -38 )

2
+
 
4x8 - 3x5
2 5x8 8x5

 

[LCM of 5 and 8 is 40]

2
+
 
32 - 15 = 2

+

32-15 = 2 + 17
2 40 40 2 40 2 40

 

[LCM of 2 and 40 is 80]

 

2x40
+
 
17x2 = 80 + 34 = 80+(34) = 114 = 5740
2x40 40x2 80 80 80 80

 

RHS = 5740

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 /)

23 , 26 and -38

RHS = Answer: 58


SOLUTION 1 :

To verify,

( 23 + 26 ) + ( -38 )  =   23 + ( 26 + ( -38 )

LHS

2
+
 
2
+
 
-3 = 2x6 + 2x3 + -3
3 6 8 3x6 6x3 8

 

[ LCM of 3 and 6 is 18]

 

12
+
 
6 + -3
18 18 8

 

12+6
+
 
-3  = 18 -3 18 3
18  8 18 8 18 8

 

[LCM of 18 ans 8 is 144]

18x8
-
 
3x18 = 144 - 54 = 144- 54 = 90 = 58
18x8 8x18 144 144 144 144

 

LHS = 58

 

RHS   23 + ( 26 + ( -38 )  =   23 + ( 26 -38 )

2
+
 
2x8 - 3x6
3 6x8 8x6

 

[LCM of 6 and 8 is 48]

2
+
 
16 - 18 = 2

+

16-18 = 2 + -2
3 48 48 3 48 3 48

 

[LCM of 3 and 48 is 144]

 

2x48
+
 
-2x3 = 96 + -6 = 96+(-6) = 90 = 58
3x48 48x3 144 144 144 144

 

RHS = 58

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 /)

24 , 54 and -25

RHS = Answer: 2720


SOLUTION 1 :

To verify,

( 24 + 54 ) + ( -25 )  =   24 + ( 54 + ( -25 )

LHS

2
+
 
5
+
 
-2 = 2x4 + 5x4 + -2
4 4 5 4x4 4x4 5

 

[ LCM of 4 and 4 is 16]

 

8
+
 
20 + -2
16 16 5

 

8+20
+
 
-2  = 28 -2 28 2
16  5 16 5 16 5

 

[LCM of 16 ans 5 is 80]

28x5
-
 
2x16 = 140 - 32 = 140- 32 = 108 = 2720
16x5 5x16 80 80 80 80

 

LHS = 2720

 

RHS   24 + ( 54 + ( -25 )  =   24 + ( 54 -25 )

2
+
 
5x5 - 2x4
4 4x5 5x4

 

[LCM of 4 and 5 is 20]

2
+
 
25 - 8 = 2

+

25-8 = 2 + 17
4 20 20 4 20 4 20

 

[LCM of 4 and 20 is 80]

 

2x20
+
 
17x4 = 40 + 68 = 40+(68) = 108 = 2720
4x20 20x4 80 80 80 80

 

RHS = 2720

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 /)

32 , 36 and -35

RHS = Answer: 75


SOLUTION 1 :

To verify,

( 32 + 36 ) + ( -35 )  =   32 + ( 36 + ( -35 )

LHS

3
+
 
3
+
 
-3 = 3x6 + 3x2 + -3
2 6 5 2x6 6x2 5

 

[ LCM of 2 and 6 is 12]

 

18
+
 
6 + -3
12 12 5

 

18+6
+
 
-3  = 24 -3 24 3
12  5 12 5 12 5

 

[LCM of 12 ans 5 is 60]

24x5
-
 
3x12 = 120 - 36 = 120- 36 = 84 = 75
12x5 5x12 60 60 60 60

 

LHS = 75

 

RHS   32 + ( 36 + ( -35 )  =   32 + ( 36 -35 )

3
+
 
3x5 - 3x6
2 6x5 5x6

 

[LCM of 6 and 5 is 30]

3
+
 
15 - 18 = 3

+

15-18 = 3 + -3
2 30 30 2 30 2 30

 

[LCM of 2 and 30 is 60]

 

3x30
+
 
-3x2 = 90 + -6 = 90+(-6) = 84 = 75
2x30 30x2 60 60 60 60

 

RHS = 75

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 /)

24 , 35 and -47

RHS = Answer: 3770


SOLUTION 1 :

To verify,

( 24 + 35 ) + ( -47 )  =   24 + ( 35 + ( -47 )

LHS

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

 

[ LCM of 4 and 5 is 20]

 

10
+
 
12 + -4
20 20 7

 

10+12
+
 
-4  = 22 -4 22 4
20  7 20 7 20 7

 

[LCM of 20 ans 7 is 140]

22x7
-
 
4x20 = 154 - 80 = 154- 80 = 74 = 3770
20x7 7x20 140 140 140 140

 

LHS = 3770

 

RHS   24 + ( 35 + ( -47 )  =   24 + ( 35 -47 )

2
+
 
3x7 - 4x5
4 5x7 7x5

 

[LCM of 5 and 7 is 35]

2
+
 
21 - 20 = 2

+

21-20 = 2 + 1
4 35 35 4 35 4 35

 

[LCM of 4 and 35 is 140]

 

2x35
+
 
1x4 = 70 + 4 = 70+(4) = 74 = 3770
4x35 35x4 140 140 140 140

 

RHS = 3770

LHS = RHS

Hence, associative property is true for addition.