Logical Deduction & Selecting Words

<p>Logical deduction questions test your ability to reason carefully and draw conclusions from given statements. These are among the trickiest verbal reasoning questions, but with a clear method, you can tackle them confidently.</p>

<h2>What Is Logical Deduction?</h2>

<p>You are given a set of statements (facts) and must work out what must be true, what must be false, or what is uncertain based on those statements — and ONLY those statements. You must ignore anything you know from real life.</p>

<p><strong>Worked Example:</strong> All cats have tails. Whiskers is a cat. What can we deduce?</p>

<p>Since all cats have tails, and Whiskers is a cat, we can deduce that Whiskers has a tail. This must be true based on the statements.</p>

<h2>Selecting the Correct Word</h2>

<p>Some questions give you a sentence with a missing word and ask you to choose the word that makes the sentence true based on the given facts.</p>

<p><strong>Worked Example:</strong> Fact: All birds have feathers. Fact: Robins are birds. Statement: Robins (always / sometimes / never) have feathers.</p>

<p>Since ALL birds have feathers and robins ARE birds, robins ALWAYS have feathers.</p>

<p><strong>Worked Example:</strong> Fact: Some sweets are red. Fact: All red sweets are strawberry-flavoured. Statement: (All / Some / No) sweets are strawberry-flavoured.</p>

<p>We know SOME sweets are red, and all red ones are strawberry-flavoured. So at least some sweets are strawberry-flavoured. But we do not know if ALL sweets are. Answer: SOME.</p>

<h2>Common Logical Traps</h2>

<p><strong>Trap 1: Reversing the logic.</strong> "All dogs are animals" does NOT mean "All animals are dogs." Just because all dogs are animals, we cannot say every animal is a dog — cats, birds, and fish are animals too.</p>

<p><strong>Trap 2: "Some" does not mean "all."</strong> If "some pupils like maths," we cannot conclude that ALL pupils like maths, nor that a specific pupil likes maths.</p>

<p><strong>Trap 3: Adding your own knowledge.</strong> If the question says "all fish can fly," you must accept that as true for the question, even though it is false in real life.</p>

<h2>Working Through Multi-Step Problems</h2>

<p><strong>Worked Example:</strong> All Year 6 pupils study French. Tom is in Year 6. Only pupils who study French go on the Paris trip. Can Tom go on the Paris trip?</p>

<p>Step 1: Tom is in Year 6 → Tom studies French (because all Year 6 pupils do).<br>

Step 2: Tom studies French → Tom can go on the Paris trip (because only French students go).<br>

Answer: Yes, Tom can go on the Paris trip.</p>

<h2>"Must Be True" vs "Could Be True" vs "Cannot Be True"</h2>

<p>These distinctions are important:</p>

<ul>

<li><strong>Must be true:</strong> there is no way it can be false given the facts</li>

<li><strong>Could be true:</strong> it is possible but not certain</li>

<li><strong>Cannot be true:</strong> it contradicts the facts</li>

</ul>

<p><strong>Worked Example:</strong> All teachers drink coffee. Mr Smith works at the school.</p>

<p>"Mr Smith drinks coffee" — could be true (if he is a teacher) but we do not know he IS a teacher. He might be a caretaker. So this COULD be true but does not HAVE to be.</p>

<h2>Practice Tips</h2>

<ul>

<li>Read each statement very carefully — one word (like "all," "some," or "no") changes everything</li>

<li>Do not bring in outside knowledge — only use the facts you are given</li>

<li>Draw quick diagrams: circles (Venn diagrams) can help you see relationships</li>

<li>For multi-step problems, write out each step so you do not lose track</li>

<li>If you are stuck, test each answer option by trying to find a scenario where it would be wrong</li>

</ul>