UCAT Syllogisms: Master Decision Making Logic Questions (UK Guide)

Why syllogisms matter for UCAT (and your medical/dental application) 🩺🦷

If you’re applying to Medicine or Dentistry in the UK, there’s a strong chance you’ll need the UCAT as part of your admissions process. The UCAT is designed to assess ways of thinking that universities value in future clinicians: making careful judgements, dealing with uncertainty, and drawing conclusions from limited information.

Within UCAT, Decision Making tests your ability to apply logic, evaluate arguments and interpret information. Syllogisms are a major “logic skills” component in this subtest — and the good news is that syllogisms improve quickly with the right method.

🟦 Encouraging truth: Syllogisms aren’t about being “naturally clever”. They’re about using a repeatable process, calmly and consistently.

UCAT Decision Making in 2025 and beyond: what you need to know ✅

Before you revise, make sure you’re preparing for the current UCAT format.

From 2025, the UCAT changed structure: Abstract Reasoning was withdrawn, leaving three cognitive subtests (Verbal Reasoning, Decision Making and Quantitative Reasoning) plus the Situational Judgement Test. Decision Making has 35 questions in 37 minutes (plus its own timed instructions screen).

Decision Making scoring is also important to understand:

• UCAT is scored by number of correct answers.

• There is no negative marking (so educated guessing is often sensible).

• In Decision Making, single-answer questions are worth 1 mark.

• Multiple-statement questions are worth 2 marks, with partial credit available for partially correct responses.

This matters for syllogisms because many syllogism sets use the Yes/No for multiple statements format — meaning your accuracy can be rewarded even if you’re not perfect.

What is a syllogism in UCAT Decision Making? (Simple definition) 🧠

A syllogism is a short logic task where you are given premises (statements presented as true for the purpose of the question), and you must decide whether a conclusion (or a set of statements) follows logically.

The key UCAT rule 🔑

You must treat the premises like they are the only facts you have.

✅ Use only what’s written.
❌ Do not use outside knowledge.
❌ Do not assume “what is likely” or “what is typical in real life”.

So even if a statement sounds unrealistic, you still follow the logic strictly.

The two UCAT syllogism answer styles you’ll see

1) Single conclusion (Yes/No)

You decide whether one conclusion follows from the premises.

2) Multiple statements (Yes/No × 5)

You are shown five statements and must mark each as Yes (follows) or No (does not follow).

🟨 Timing benefit: If you have a strong method, multi-statement syllogisms can become a reliable mark source — because each statement is usually just a small logical check.

The language of syllogisms: key words you must interpret correctly 📌

Syllogisms are often “easy” until the wording gets slippery. UCAT commonly uses quantifiers (amount words) and logic connectors (linking words).

Below are safe interpretations used in formal logic and UCAT-style reasoning.

Quantifiers (amount words)

• All A are B → every A is inside group B

• No A are B → A and B do not overlap

• Some A are B → at least one thing is both A and B (could be more)

• Some A are not B → at least one A exists outside B

• Most A are B → more than half of A are B (but not necessarily all)

Logic connectors (linking words)

These appear less often, but they are high value if you learn them properly:

• Only

  • “Only A are B” means: if something is B, it must be A.

  • A helpful translation: B → A (B is a subset of A).

  • Many students flip this by mistake.

• Unless

  • “B unless A” usually means: If not A, then B.

  • Another equivalent: A or B (at least one must be true).

• Either…or

  • Usually treated as one or the other (not both) unless the question clearly allows both.

🟥 Common problem: Students read syllogisms like English comprehension. You must read them like maths relationships between groups.

The “Set Map” method: a step-by-step approach that works under time pressure 🗺️✅

This is a practical method to use in timed practice and the real exam.

Step 1: Identify the groups (the “nouns”)

Circle or note the categories, e.g.:

• dentists

• surgeons

• researchers

• volunteers

Step 2: Convert each premise into a simple relationship

You can do this in plain English (no fancy symbols required):

• “All A are B” → A is inside B

• “No A are B” → A is separate from B

• “Some A are B” → A overlaps B

• “Some A are not B” → part of A is outside B

Step 3: Test the conclusion with the “always true?” question

A conclusion follows only if it must be true in every situation that fits the premises.

If you can imagine even one valid situation where the premises are true but the conclusion is false, then it does not follow.

🟦 This is the single biggest upgrade you can make:
Syllogisms are about certainty, not probability.

Worked examples (UCAT-style) with clear explanations ✍️

Example 1: The classic “reversal trap”

Premise: All dentists are healthcare professionals.
Conclusion: All healthcare professionals are dentists.

✅ Premise tells you dentists are within healthcare professionals.
❌ It does not say healthcare professionals are only dentists.

🟥 Answer: Does not follow.

Why: Nurses, doctors and paramedics could also be healthcare professionals.

Example 2: “Some” does not mean “all”

Premise: Some students are volunteers.
Conclusion: All students are volunteers.

🟥 Answer: Does not follow.

Why: “Some” only guarantees at least one. It leaves open the possibility that many (or most) students are not volunteers.

Example 3: When “No” can be reversed

Premise: No surgeons are dentists.
Conclusion: No dentists are surgeons.

🟩 Answer: Follows.

Why: If two groups do not overlap in one direction, they do not overlap in the other direction either.

Example 4: A more realistic UCAT multi-step check

Premise 1: All applicants who attend an interview are shortlisted.
Premise 2: Some shortlisted applicants are international.
Conclusion: Some applicants who attend an interview are international.

🟥 Answer: Does not follow.

Why: Premise 2 tells you some shortlisted applicants are international, but it never says those international shortlisted applicants are the ones who attend interviews. They might be shortlisted but not interviewed.

The fastest syllogism shortcut: the “counterexample test” ⚡

When you’re stuck, ask:

“Can I build a situation where the premises are true, but the conclusion is false?”

If yes → does not follow.

This is especially powerful for:

• conclusions involving all

• conclusions involving most

• conclusions that “jump” between groups without a clear link

High-frequency traps (and how to avoid them) ⚠️

Trap 1: Flipping “All”

• Premise: All A are B

• Wrong conclusion: All B are A
  ✅ Fix: Remember only one direction is guaranteed.

Trap 2: Treating “Some” like “Most”

• “Some” could be a tiny overlap.
  ✅ Fix: Assume the minimum that still makes the statement true.

Trap 3: “Only” confusion

• “Only doctors are prescribers” means if prescriber → doctor
  ✅ Fix: Rephrase as “Prescribers must be doctors.”

Trap 4: Adding real-world assumptions

• “All dentists like science” might be unrealistic — irrelevant.
  ✅ Fix: Treat it as true within the question.

Trap 5: Over-diagramming

Venn diagrams can help, but drawing a perfect diagram for every question can slow you down.
✅ Fix: Use a quick sketch only when relationships are hard to hold in your head.

Timing and marks: how to maximise your score in syllogisms ⏱️📈

Decision Making is tight on time. A good target mindset is:

• Keep moving.

• Protect accuracy on questions you can do.

• Don’t donate minutes to one stubborn statement.

Practical exam tactics

✅ If a conclusion is clearly unsupported, answer quickly and move on.
✅ If you’re unsure, try the counterexample test rather than re-reading repeatedly.
✅ If it’s a multi-statement set, don’t panic: treat each statement as a mini-question.
✅ Flag and return only if you have a reliable method and genuinely think you’ll improve it later.

🟨 Because UCAT has no negative marking, leaving blanks is rarely the best strategy. Even a reasoned guess can be worthwhile.

How to practise syllogisms effectively (without burning out) 💡

Phase 1: Learn the patterns (untimed)

Aim: build confidence and accuracy.

• Do small sets (5–10 questions)

• After each set, write down:

  • Which keyword fooled you? (only, some, most, etc.)

  • Was it a reversal mistake?

  • Did you assume extra information?

Phase 2: Timed sets with reflection (the score booster)

Aim: keep accuracy while speeding up.

• Do 10–15 minutes timed syllogisms

• Review immediately

• Create a “trap list” you reread before each practice session

Phase 3: Mixed Decision Making practice (the exam reality)

Syllogisms don’t appear in isolation on test day. Train your brain to switch styles:

• syllogisms

• Venn/Euler

• probability

• arguments

• logic puzzles

This reduces the “gear change” time that quietly drains minutes in the real UCAT.

A simple 14-day syllogism mini-plan (doable alongside sixth form) 📚

Days 1–3: Foundations

• Learn the meanings of: all / no / some / some…not / most / only / unless

• 20–30 syllogism questions untimed, focusing on method

Days 4–7: Accuracy

• 30–50 questions across the week

• Review errors carefully (this is where improvement happens)

Days 8–11: Timing

• 4 sessions of 10–15 minutes timed syllogisms

• Record:

  • accuracy %

  • which keywords caused mistakes

  • average time per statement

Days 12–14: Mixed DM sets

• Timed mixed Decision Making practice

• Keep syllogisms calm and methodical, even when you’re tired

Syllogisms FAQ (the questions students actually ask) 🙋‍♀️🙋‍♂️

“Do I need prior knowledge for UCAT syllogisms?”

No. You should rely only on the information in the question. UCAT is intended to assess aptitude rather than learned subject content.

“What if a premise sounds unrealistic?”

Ignore realism. Treat premises as true for the purpose of the question.

“Should I always draw a Venn diagram?”

Not always. Use a quick sketch when it genuinely clarifies the relationships — otherwise, your best tool is a clean step-by-step translation + counterexample test.

“How do top scorers get fast at syllogisms?”

They don’t read faster — they translate faster. Speed comes from recognising repeated logic structures and avoiding the same traps.

Key takeaways (save this for your revision notes) ✅

• Syllogisms test certainty: does the conclusion follow in every valid case?

• Translate wording into group relationships.

• Watch for the big traps: reversals, some vs all, and only.

• Use the counterexample test when unsure.

• Practise in phases: untimed accuracy → timed sets → mixed DM.