1.

Which of the following is definitely TRUE?1. x ∈ A and A ∉ B, then x ∉ B2. x ∉ A and B ⊂ A, then x ∉  B3. A ⊂ C and B ⊂ C, then A = B4. A ⊂ C and B ⊂ C, then (A∪B) = C

Answer» Correct Answer - Option 2 : x ∉ A and B ⊂ A, then x ∉  B

Concept:

Set theory:

  • A ∪ B means set of all the values in the set A and B.
  • ∩ B is the set of common elements of A and B.
  • Subset (⊂) is the set such that all the elements of the subset are in the set from which the subset is taken from.

 

Calculation:

Taking any arbitrary example

Let A = {1, 3}, B = {3} and C = {1, 2, 3, 4, 5, 6}

Now, A ∪ B = {1, 3}

Case 1: If x = 3 , then x ∈ A, and A ∉ B, but x ∈ B (option 1 false)

Case 2: If x = 3 , then x ∉ A, and B ⊂ A, then x ∉  B (option 2 true)

Case 3:  A ⊂ C and B ⊂ C, but A ≠ B (option 3 false)

Case 4: A ⊂ C and B ⊂ C, but (A ∪ B) ≠  C (option 4 false)



Discussion

No Comment Found

Related InterviewSolutions