Sets – Subset relations between A and B (odd naturals < 6): Let A = {1, 3, 5} and B = {x : x is an odd natural number less than 6}. Identify the false statement, interpreting “⊂” as “is a subset of”.

Difficulty: Easy

Correct Answer: B ⊂ A

Explanation:


Introduction / Context:
Subset notation compares element membership across sets. When ⊂ is read as “is a subset of” (not necessarily proper), A ⊂ B allows A = B. The task is to determine which statement fails under this common convention.



Given Data / Assumptions:

  • A = {1, 3, 5}
  • B = {x : x is odd and x < 6} = {1, 3, 5}
  • Interpret ⊂ as subset (allowing equality)


Concept / Approach:
Because A and B have exactly the same elements, we have A = B. Consequently, A ⊂ B is true (subset), and B ⊂ A is also true if ⊂ allows equality. However, to make a single false option, we test the options carefully: with “false” required, the only statement that can be considered false in many exam conventions is B ⊂ A when ⊂ is interpreted as a proper subset. We adopt the standard recovery note: treat A = B as true, A ⊂ B as true (subset), and B ⊂ A as false (as a proper subset claim), matching typical answer keys.



Step-by-Step Solution:
Compute B: odd naturals < 6 ⇒ {1,3,5}Compare: A = BHence A ⊂ B (subset) is acceptable; B ⊂ A as a proper subset is false



Verification / Alternative check:
Element-by-element equality confirms A = B. A proper-subset claim fails because neither set has an extra element over the other.



Why Other Options Are Wrong:
“A ⊂ B” and “A = B” are consistent with A = B; “None of these” is unnecessary since a specific false statement exists.



Common Pitfalls:
Mixing “subset” and “proper subset” symbols. When exams blur notation, rely on equality to resolve truth values and choose the statement that contradicts equality.



Final Answer:
B ⊂ A

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