If A ⊆ B, B ⊆ C, and A ≠ C, which statement is always true?
Answer and explanation
Correct answer: A ⊂ C; A is a proper subset of C
Subset inclusion is transitive: from A ⊆ B and B ⊆ C, we obtain A ⊆ C. The additional condition A ≠ C rules out equality, so A must be a proper subset of C, written A ⊂ C. Nothing in the conditions forces B to equal either A or C, so options B and C are not always true.
Frequently asked questions
What is the correct answer to this question?
A ⊂ C; A is a proper subset of C
Why is this the correct answer?
Subset inclusion is transitive: from A ⊆ B and B ⊆ C, we obtain A ⊆ C. The additional condition A ≠ C rules out equality, so A must be a proper subset of C, written A ⊂ C. Nothing in the conditions forces B to equal either A or C, so options B and C are not always true.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Power Set and Subsets.