If the statement 'All tigers are mammals', is given as true, which of the following statements could be immediately inferred to be false?

A. Some tigers are not mammals.

B. Some tigers are mammals.

C. No tigers are mammals.

D. Some mammals are tigers.

Choose the correct answer from the options given below: 

The correct answer is A and C only.
Key PointsIf the statement "All tigers are mammals" is given as true, then we know that every tiger is a mammal.

Statement A, "Some tigers are not mammals"

• It is immediately inferred to be false.
• This is because the given statement asserts that all tigers are mammals, so it cannot be true that some tigers are not mammals.

Statement B, "Some tigers are mammals",

• It is immediately inferred to be true.
• This is because the given statement asserts that all tigers are mammals, and if every tiger is a mammal, then it must be true that some tigers are mammals.

Statement C, "No tigers are mammals",

• It is immediately inferred to be false.
• This is because the given statement asserts that all tigers are mammals, so it cannot be true that no tigers are mammals.

Statement D, "Some mammals are tigers",

• It is not immediately inferred to be either true or false.
• The given statement only tells us that every tiger is a mammal, but it does not tell us anything about whether there are other mammals that are not tigers.

Therefore, statement D could be true or false, depending on the other mammals that exist.

In summary, the correct answer is  A and C only.