This is a Data Sufficiency question testing inequalities with weighted sums — one of the sneakier DS patterns because it looks like you need exact numbers when you really don't.
First, let's set up the question. Let T = tables and C = chairs made last week. Total wood = 100T + 25C. We need to know: is 100T + 25C > 20,000? Dividing everything by 25, this simplifies to: is 4T + C > 800?
Statement 1: T + C > 800Here's the key insight. We need 4T + C > 800, and we know T + C > 800. Rewrite our target: 4T + C = (T + C) + 3T. Since T represents a count of tables, T >= 0, so 3T >= 0. That means 4T + C = (T + C) + 3T >= (T + C) > 800. Done — the answer to the question is always YES.
Statement 1 is sufficient.
Statement 2: T > CThis tells us about the ratio of tables to chairs but nothing about the total quantity. If T = 1 and C = 0, total wood = 100 (not > 20,000). If T = 201 and C = 0, total wood = 20,100 (yes > 20,000). We can get both YES and NO answers.
Statement 2 is not sufficient.
Answer: (A)Common trap: The mistake I see most often on this type is jumping into testing specific numbers for Statement 1 without first simplifying the algebra. Students try cases like "what if 500 tables and 301 chairs" and end up spending 3 minutes on something you can prove in 30 seconds with the inequality relationship. In DS, always ask: can I compare the given information directly to what I need, without finding exact values?
Takeaway: When a DS question asks about a weighted sum and gives you information about an unweighted sum, check whether the weights being >= 1 (or all positive) automatically make the weighted version larger — that one-line comparison can save you a ton of time.