Exercise 1.3, Unit-1, SETS, Mathematics 7, Punjab Curriculum and Textbook Board

EXERCISE 1.3 

1. Look at each pair of sets to separate the disjoint and overlapping sets. 

(i) A = {a, b, c, d, e},    B = {d, e, f, g, h} 
(ii) L = {2, 4, 6, 8, 10}, M = {3, 6, 9, 12} 
(iii) P = Set of Prime numbers, C = Set of Composite numbers 
(iv) E = Set of Even numbers,  O = Set of Odd numbers 

Answers:
Disjoint Sets: Options (iii) and (iv) are disjoint sets
(Because there are some Common Elements in both sets.)

Overlapping Sets: Options (i) and (ii) are overlapping sets
(Because there are NO Common Elements in both sets.)

2. If U = {1, 2, 3, ...., 10}, A = {1, 2, 3, 4, 5}, B = {1, 3, 5, 7, 9}, C = {2, 4, 6, 8, 10} and D = 3, 4, 5, 6, 7}, then find: 
(i) A' (ii) B' (iii) C' (iv) D'

(i) A'

Solution:  

U = {1, 2, 3, ...., 10}, A = {1, 2, 3, 4, 5}

A' = U \ {1, 2, 3, ...., 10} {1, 2, 3, 4, 5}

                { 6, 7, 8, 9, 10} .......Ans


(ii) B'

Solution:  

U = {1, 2, 3, ...., 10}, B = {1, 3, 5, 7, 9}

B' = U \ {1, 2, 3, ...., 10} {1, 3, 5, 7, 9}

                { 2, 4, 6, 8, 10} .......Ans


(iii) C'

Solution:  

U = {1, 2, 3, ...., 10}, C = {2, 4, 6, 8, 10}

C' = U \ {1, 2, 3, ...., 10} {2, 4, 6, 8, 10}

                 { 1, 3, 5, 7, 9} .......Ans


(iv) D'

Solution:  

U = {1, 2, 3, ...., 10}, D = { 3, 4, 5, 6, 7}

D' = U \ {1, 2, 3, ...., 10} 3, 4, 5, 6, 7}

                 { 1, 2, 8, 9, 10} .......Ans




3. If U = {a, b, c,...., i }, X = {a, c, e, g, i}, Y = {a, e, i}, and Z = {a, g, h}, then find: 
(i) X' (ii) Y' (iii) Z' (iv) U' 


(i) X'

Solution:  

U = {a, b, c,...., i },  X = {a, c, e, g, i}

A' = U \ {a, b, c,...., i } {a, c, e, g, i}

                {b, d, f, h } .......Ans


(ii) Y'

Solution:  

U = {a, b, c,...., i }, Y = {a, e, i}

B' = U \ {a, b, c,...., i } {a, e, i}

                {b, c, d, f, g, h } .......Ans


(iii) Z'

Solution:  

U = {a, b, c,...., i }, Z = {a, g, h}

C' = U \ {a, b, c,...., i } {a, g, h}

                 {b, c, d, e, f, i } .......Ans


(iv) U'

Solution:  

U = {a, b, c,...., i }

U' = U \ U {a, b, c,...., i } {a, b, c,...., i }

                 {  } .......Ans



4. If U= {1, 2, 3, ..., 20}, A= {1, 3, 5, ... ,19} and B = {2, 4, 6, ... ,20}, then prove that: 
(i) B' = A (ii) A' = B (iii) A \ B = A (iv) B \ A = B 


(i) B' = A

Solution:  

U = {1, 2, 3, ..., 20 },  A= {1, 3, 5, ... ,19}, B = {2, 4, 6, ... ,20}

L.H.S  = B' = U \ B 

                   {1, 2, 3, ..., 20 } {2, 4, 6, ... ,20}

                   {1, 3, 5, ... ,19 }

                   = R.H.S

Hence Verified that 

L.H.S =   R.H.S 

B'       =      A


(ii) A' = B

Solution:  

U = {1, 2, 3, ..., 20 },  A= {1, 3, 5, ... ,19}B = {2, 4, 6, ... ,20}

L.H.S  A'  = U \ 

                   {1, 2, 3, ..., 20 } {1, 3, 5, ... ,19}

                   = {2, 4, 6, ... ,20 }

                   = R.H.S

It is Verified that 

L.H.S =   R.H.S 

A'       =      B


(iii) A \ B = A

Solution:  

A= {1, 3, 5, ... ,19}B = {2, 4, 6, ... ,20}

L.H.S  A \ 

           {1, 3, 5, ... ,19 } {2, 4, 6, ... ,20}

           {1, 3, 5, ... ,19 }

           = A R.H.S

It is Verified that 

L.H.S    =   R.H.S 

A \      =   A


(iv) B \ A = B

Solution:  

A= {1, 3, 5, ... ,19}B = {2, 4, 6, ... ,20}

L.H.S  A 

           {2, 4, 6, ... ,20} {1, 3, 5, ... ,19}

           {2, 4, 6, ... ,20}

           B = R.H.S

It is Verified that 

L.H.S    =   R.H.S 

A      =   B



5. If U = set of integers and W = set of whole numbers, then find the complement of set W. 

Solution:  

U = Set of integers = {0, ± 1, ± 2, ± 3,...},
  
W = set of whole numbers = {0, 1, 3, 5, .....}

W' = U \ {0, ± 1, ± 2, ± 3,...} {0, 1, 3, 5, .....}

                  = { -1, -2, -3,......} .......Ans



6. If U = set of natural numbers and P = set of prime numbers, then find the complement of set P.

Solution:  

U = Set of Natural Numbers = {1, 2, 3,.....},  

P = set of Prime numbers = { 2, 3, 5, 7, 11, 13 .....}

P' = U \ {1, 2, 3,.....} { 2, 3, 5, 7, 11, 13 .....}

                  = { 1, 4, 6, 8, 9, 10, 12, 15 .....} .......Ans

************************

Job & Exam Mathematics Rare (JEMrare)

***************************************************************

Shortcut links for:




************************************

1. Website for School and College Level Physics   
2. Website for School and College Level Mathematics  
3. Website for Single National Curriculum Pakistan - All Subjects Notes 

© 2022-23  Academic Skills and Knowledge (ASK    

Note:  Write me in the comments box below for any query and also Share this information with your class-fellows and friends.


Post a Comment

0 Comments

cwebp -q 80 image.png -o image.webp