- AIf (A – B) C, then A C
- BB C
- C(C A) (C B) = C
- DIf (A – C) B, then A B
View written solutionFree
Correct answer: D
We are given and we must find which statement is not true.
1. Interpret the condition
The given condition means:
- every element common to both and must belong to .
Equivalently,
We now test each option.
2. Option A
Statement: If , then .
Recall
Given:
- and from the question,
Therefore both parts of are contained in . Hence
So Option A is true.
3. Option B
The printed option appears as: which is clearly a typographical issue. In such set notation, this is intended to mean
Now check whether this must be true from .
It need not be true.
Take a counterexample:
Then , but here so this example does not disprove it.
Try another:
Then which satisfies the condition. But So the statement is false in this case.
Hence Option B is not always true.
4. Option C
Statement:
Use the distributive identity:
So,
Given , we get
Therefore,
So Option C is true.
5. Option D
Statement: If , then .
Now,
From the given condition , we cannot conclude that . So even if , it does not force all of to lie in .
Let us find a counterexample.
Take:
Then so the given condition holds.
Also,
But
Thus the implication in Option D is false.
So Option D is not true.
6. Conclusion
From the valid interpretation of the options:
- A is true
- C is true
- D is false
Option B, as printed, is malformed. If interpreted as , that statement is also not always true. However, in standard versions of this question and from the stored answer, the intended uniquely false statement is D.
Therefore the correct answer is
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