If A = {0, ∅, {0}}, how many elements does A have?
Answer and explanation
Correct answer: 3
The outer braces define the set A. Inside them are three distinct objects: the number 0, the empty set ∅, and the singleton set {0}. Although {0} contains 0 as its own element, it is not the same object as 0. Likewise, ∅ is a set with no elements. Thus A has three elements, so its cardinality is 3.
Frequently asked questions
What is the correct answer to this question?
3
Why is this the correct answer?
The outer braces define the set A. Inside them are three distinct objects: the number 0, the empty set ∅, and the singleton set {0}. Although {0} contains 0 as its own element, it is not the same object as 0. Likewise, ∅ is a set with no elements. Thus A has three elements, so its cardinality is 3.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.