OC Thinking Skills Practice Test 16 — 2027 NSW Opportunity Class Exam

Let's draw our imaginary circles to find out exactly where the trap is hiding.

Step 1: The "Inside" Rule "All superheroes wear capes." This means the Superhero circle is completely hidden inside the giant Cape Wearers circle.

Step 2: The "Maybe" Overlap "Some people who wear capes are afraid of heights." This means there is an overlap between the Cape Wearers and the Afraid of Heights group.

The Danger Zone: We don't know if the "Afraid of Heights" circle touches the "Superheroes" at all! They are both inside the "Capes" circle, but they might be on totally opposite sides. Maybe superheroes love flying!

Step 3: The "Must" Chain "Everyone who is afraid of heights must take the stairs." This means the entire Afraid of Heights circle is trapped completely inside the Stairs circle.

Step 4: Finding the Truth Let's look closely at the overlap from Step 2. We know for a fact there is a group of people who both wear capes AND are afraid of heights. Because every single person who is afraid of heights has to take the stairs, those specific cape-wearers must be walking up the steps!

This proves that at least some people who take the stairs wear capes.

Why the others are traps:

• A & C: These are the traps! Your brain wants to connect the Superheroes to being afraid of heights, but the rules don't let us cross that bridge. We can't prove they are afraid, so we can't prove they need the stairs.

• D: We don't know this either. The rules don't say superheroes aren't afraid of heights; they just don't guarantee that they are.

Correct Answer: B

Did you spot the trap this time? Once you learn to stop your brain from jumping across circles that don't definitely touch, these OC questions become much easier!

Let's solve this slowly, one step at a time.

What is this question asking? No two snowflakes can be exactly the same. Last week, a famous chemist examined fifty different snowflakes under a powerful microscope. After careful consideration, he announced that two of the specimens were identical. Clearly, his conclusion must be mistaken.

How to think about it: The passage ends with: "Clearly, his conclusion must be mistaken." That is the main conclusion — the chemist was wrong to say two snowflakes were identical.

• A ("No two snowflakes can be exactly the same") is the opening premise — it is the reason used to reach the conclusion, not the conclusion itself.
• B ("No two snowflakes were identical") is just a restatement of that same premise.
• D ("All of the above") is wrong because A and B are premises, not the main conclusion.
• C ✓ ("The chemist's conclusion that the two snowflakes were identical must be incorrect") is a direct restatement of what the passage concludes.

Final answer: Option C (The famous chemist's conclusion that the two snowflakes were identical must be incorrect.). Self-check tip: identify the final claim the passage is arguing FOR — that is the main conclusion.