Question

if n(A)=2,n(B)=3 and n(AintersectionB)=1 then n(AunionB)

Answer 1

HERE IS UR ANSWER DEAR

n(AUB) = n(A) +n(B) -n(AnB)

= 2+3-1 = 3+1 = 4

Answer 2

Given :

• n ( A ) = 2
• n ( B ) = 3
• n ( A ∩ B ) = 1

To find :

• n ( A ∪ B ) =?

Knowledge required :

• For two finite sets A and B

     n ( A ∪ B ) = n ( A ) + n ( B ) - n ( A ∩ B )

Solution :

Using formula

→ n ( A ∪ B ) = n ( A ) + n ( B ) - n ( A ∩ B )

putting values

→ n ( A ∪ B ) = ( 2 ) + ( 3 ) - ( 1 )

→ n ( A ∪ B ) = 5 - 1

→ n ( A ∪ B ) = 4

Therefore,

• Number of Elements in Union of sets A and B will be, n ( A ∪ B ) = 4.

More to know :

Union of Sets: Let A and B be two sets, then Union of A and B is te set of all those elements which belong to either or B or both A and B.

• It is denoted as: A ∪ B
• so, A ∪ B = { x : x ∈ A or x ∈ B }

Intersection of Sets: Let A and B be two sets, then The intersection of A and B is the set of all elements that belong to both A and B.

• It is denoted as: A ∩ B
• so, A ∩ B = { x : x ∈ A and x ∈ B }.