Sets A and B have 3 and 6 elements each. What can be the minimum number of elements in AUB?
Option
(a) 3
(b) 6
(c) 9
(d) 18
(e) 24

• n(AuB)=n(A)+n(B)-n(A B)
  3. + 6. - 3
  =6
  
• 10 years agoHelpfull: Yes(43) No(1)
• We have, n (A U B) = n(A) + n(B) – n(A ∩ B)
  This shows that n (A U B) is minimum or maximum according as
  n (A ∩ B) is maximum or minimum respectively.
  Case 1: When n (A ∩ B) is minimum, ie. n (A ∩ B) = 0. This is possible only when A ∩ B = ?. In this case,
  n(A U B) = n (A) + n (B) – 0 = n(A) + n (B) = 3 +6 = 9
  n (A U B)max = 9
  Case 2: When n (A ∩ B) is maximum
  This is possible only when A ⊆ B.
  In this case n (A ∩ B) = 3
  n (A U B) = n(A) + n(B) – n (A ∩ B) = (3+6-3)=6
  n (A U B)min = 6.
• 9 years agoHelpfull: Yes(10) No(0)
• 6 is right. ans
• 10 years agoHelpfull: Yes(4) No(2)
• for minmum AUB, AnB should b maximum i.e 3. so n(AuB)=n(A)+n(B)-n(A B)
  3. + 6. - 3
  =6
• 9 years agoHelpfull: Yes(4) No(0)
• ans 6.
  
  
  
  
• 10 years agoHelpfull: Yes(3) No(2)
• how n(AnB)=3?
• 9 years agoHelpfull: Yes(1) No(1)
• how how n(AnB)=3?
• 9 years agoHelpfull: Yes(1) No(1)
• let set A = (a,b,c)
  set B =(a,b,c,d,e.f)
  then A U B =(a,b,,c,d,e,f)
  which have 6 elements
• 8 years agoHelpfull: Yes(1) No(1)
• Let A = {1,2,3} and B = {1,2,3,4,5,6}
  min no. of elements in n(AuB)= 3+6-3= 6
  Opt: b is correct
• 8 years agoHelpfull: Yes(1) No(0)
• For minimum union :
  The large set have all the elements which is kept in small set. i,e B contains all elements of A
  So, union will give the number of elements in large set, i.e 6;
  Ans: (b) 6
• 7 years agoHelpfull: Yes(0) No(0)
• 6
  As B has 6 elements, so it is obvious that the minimum number of elements in AUB would be 6
• 6 years agoHelpfull: Yes(0) No(0)
• Ans - 6
  Explanation : In union of two set if All the element of set 1 is present In Set 2 (Where n(S1 ) < n(S2)) then there is at least n(S2) element present in Union.
  Ex: A={1,2,3}: B={1,2,3,4,5,6} then AUB ={1,2,3,4,5,6}
• 4 years agoHelpfull: Yes(0) No(0)
• Let A={1,2,3}=3
  B={1,2,3,4,5,6}=6
  (A U B)= n(A) + n(B) - n(A ∩ B)
  So, n(A ∩ B)={1,2,3}=3 (Common elements in both set A & B)
  According to Formula,
  (A U B)= n(A) + n(B) - n(A ∩ B)
  =3+6-(3)
  (A U B ) =6
• 4 years agoHelpfull: Yes(0) No(0)