If A = {1, 3, 5, 7} and B = {1, 3, 5}, why is A ⊆ B false?
Answer and explanation
Correct answer: 7 is in A but not in B
The statement A ⊆ B requires every element of A to be an element of B. Although 1, 3, and 5 occur in both sets, the element 7 belongs to A and does not belong to B. A single element of A missing from B is enough to make the subset statement false. Therefore the precise reason is that 7 is in A but not in B, which makes option A correct.
Frequently asked questions
What is the correct answer to this question?
7 is in A but not in B
Why is this the correct answer?
The statement A ⊆ B requires every element of A to be an element of B. Although 1, 3, and 5 occur in both sets, the element 7 belongs to A and does not belong to B. A single element of A missing from B is enough to make the subset statement false. Therefore the precise reason is that 7 is in A but not in B, which makes option A correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Equal sets and Subsets.
