Which of the following sets is equal to the empty set ∅?
Answer and explanation
Correct answer: {x : x is a natural number and x < 0}
There is no natural number less than 0, because natural numbers are non-negative in the usual school definition. Hence no value of x satisfies the condition in option C, so that set has no elements and equals ∅. In contrast, {0}, {1}, and {∅} each contain one element; particularly, {∅} is not the empty set.
Frequently asked questions
What is the correct answer to this question?
{x : x is a natural number and x < 0}
Why is this the correct answer?
There is no natural number less than 0, because natural numbers are non-negative in the usual school definition. Hence no value of x satisfies the condition in option C, so that set has no elements and equals ∅. In contrast, {0}, {1}, and {∅} each contain one element; particularly, {∅} is not the empty set.
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.
