If n(A − B) = 41 and n(A ∩ B) = 22, what is n(A)?
Answer and explanation
Correct answer: 63
The set A consists of two non-overlapping parts: the elements that are in A but not in B, represented by A − B, and the elements common to both A and B, represented by A ∩ B. Hence n(A) = n(A − B) + n(A ∩ B) = 41 + 22 = 63. Therefore, option B is correct. The value 41 counts only the exclusive part of A, while 22 counts only the common part.
Frequently asked questions
What is the correct answer to this question?
63
Why is this the correct answer?
The set A consists of two non-overlapping parts: the elements that are in A but not in B, represented by A − B, and the elements common to both A and B, represented by A ∩ B. Hence n(A) = n(A − B) + n(A ∩ B) = 41 + 22 = 63. Therefore, option B is correct. The value 41 counts only the exclusive part of A, while 22 counts only the common part.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
