For A = {1, 2, 3}, identify which is a PROPER subset of A.
AA itself
Bℕ
C{1, 2, 3, 4}
D{1, 2}
Answer & Solution
Correct answer: D. {1, 2}
A proper subset of A is a set B with B ⊂ A and B ≠ A. {1, 2} ⊂ A and {1, 2} ≠ A → proper subset. A itself is a subset but not proper. {1, 2, 3, 4} is a SUPERSET, not subset. ℕ ⊅ A's complement.
Related questions
U = {1, 2, ..., 10} and A = {1, 3, 5, 7, 9}. The complement of A is:A = {2, 4, 6, 8} and B = {6, 8, 10, 12}. In A union B the elements 6 and 8 appear:In a Venn diagram the universal set is usually drawn as a:The collection of all subsets of A is called the:How many subsets does {1, 2} have?The open interval (a, b) leaves out:A set with exactly one element is called a:The empty set is a subset of: