Question

Statement 1: All polymers are compounds. Statement 2: Some compounds are not plastics. Statement 3: All plastics are synthetic. Which of the following must be false?

• A. Some polymers are synthetic.
• B. Some synthetic materials are not compounds.
• C. No polymer is a plastic.
• D. All compounds are synthetic.

Hint:

When evaluating "must be false", look for the option that directly contradicts the premise.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Use syllogistic logic and Venn diagrams to check validity of statements.

Step 2: Detailed Explanation:
1. Polymer $\subset$ Compound.
2. Some Compounds $\not\subset$ Plastic.
3. Plastic $\subset$ Synthetic.
4. Checking (D): "All compounds are synthetic." Since Statement 2 says some compounds are not even plastics, and there is no information saying all compounds are synthetic, concluding "All compounds are synthetic" contradicts the general nature of compounds vs synthetic substances.

Step 3: Final Answer:
Statement (D) must be false.