Question

5. Let U = {4,8,12,16,20,24,28} A = {8,16,24} and B = {4,16,20,28} .
Find (A U B) and (A u B)l.

Answer 1

Hi ,

It is given that ,

U = { 4,8,12,16,20,24,28 }

A = { 8, 16 ,24 }

B = { 4 , 16 , 20 , 28 }

Now ,

i ) A U B = { 8 , 16 ,24 } U { 4,16,20,28}

= { 4 ,8 ,16 ,20 , 24 , 28 }

ii ) ( A U B )' = U - ( A U B )

= { 4,8,12,16,20,24,28 } -

{4,8,16,20,24,28 }

= { 12 }

I hope this helps you.

: )

Answer 2

Question :
Let U = {4,8,12,16,20,24,28} A = {8,16,24} and B = {4,16,20,28} .
Find (A U B)’ and (A ∩ B)’

Union of two sets :
The union of the sets A and B is the set of all the element that belongs to either A or B or both. It is denoted by A U B(“A union B”).
Intersection of two sets :
The intersection of the sets a and b is the set of all the elements which belong to both A and B. It is denoted by A ∩ B (“ A intersection B”).
•If A and B do not have any element in common then A ∩ B= a null set = Ø

•A’ == The complementary set of A
• To find A’ , list all the members of the universal set U which are not members of A.
(A U B )’ = A’ ∩ B’
(A ∩ B )’ = A’ U B’

SOLUTION :
GIVEN :
U = {4,8,12,16,20,24,28} A = {8,16,24} and B = {4,16,20,28}
A U B = {4,8,16,20,24,28}
Hence, (A U B )’ = U - A U B
(A U B )’ = {12}

A ∩ B = {16}
Hence,(A ∩ B )’ = U - (A ∩ B )
(A ∩ B )’ = {4.8,12,20,24,28}

HOPE THIS WILL HELP YOU….