Which of the following descriptions forms a well-defined set?
Answer and explanation
Correct answer: Odd natural numbers less than 10
A set is well-defined when it is possible to decide objectively and unambiguously whether any given object belongs to it. The odd natural numbers less than 10 are exactly 1, 3, 5, 7, and 9, so membership is definite. Words such as good, beautiful, and interesting depend on personal judgment, so they do not define well-defined sets.
Frequently asked questions
What is the correct answer to this question?
Odd natural numbers less than 10
Why is this the correct answer?
A set is well-defined when it is possible to decide objectively and unambiguously whether any given object belongs to it. The odd natural numbers less than 10 are exactly 1, 3, 5, 7, and 9, so membership is definite. Words such as good, beautiful, and interesting depend on personal judgment, so they do not define well-defined sets.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
