Given All A are B and No B are Z, No A are Z is...

• A. False.
• B. True.
• C. Not necessarily true.
• D. Cannot be determined.

Answer: (B)

Think in terms of sets. All A are B means A is contained in B. No B are Z means B has no elements that are Z, so B and Z are disjoint. Since every A is a B, and no B is Z, none of the A elements can be Z. That makes No A are Z true. This holds whether A has elements or not, because the statement asserts there are no elements that are both A and Z, which is guaranteed by the given premises. So the conclusion is a definite consequence of the two conditions.