Class XI SET THEORY MCQ SOLUTION | Sem 1
Chapter 1: Set Theory SN Dey Class 11 Math Solution For Semester - 1 MCQ Questions 1. The number of subsets of a set containing four elements is— (A) 8 (B) 8 (C) 16 (Answer) (D) 64 Solution: If a finite set A has n elements, then its power set contains 2 n elements. ∴ The number of subsets of a set with four elements is 2 4 = 16. 2. The number of proper subsets of a set containing five elements is— (A) 5 (B) 10 (C) 32 (D) 31 (Answer) Solution: The number of proper subsets of a set with five elements is 2 5 - 1 = 32 - 1 = 31. [Note: A set is a subset of itself, but it is not a proper subset]. 3. If x ∈ A ⇒ x ∈ B , then— (A) A = B (B) A ⊂ B (C) A ⊆ B (Answer) (D) B ⊆ A 4. If A ⊆ B and B ⊆ A , then— (A) A = ϕ (B) A ∩ B = ϕ (C) A = B (Answer) ...