LSAT Inference Practice Question: Conditional Chain
An original inference question from our free Question of the Day rotation, built around a trap the LSAT reuses constantly: conditional chain. Try it first, then read the explanation — it teaches the move, not just the answer.
Your job:Find what the statements force to be true.
Pinecrest Outfitters rents kayaks and canoes at Lake Tarn. Every kayak in Pinecrest's fleet is a single-seater. In April, Pinecrest inspected all of the single-seat boats in its fleet.
If the statements above are true, which one of the following must also be true?
Show the answer & full explanation
The correct answer is A
The JBDM line
Just because every single-seater was inspected doesn't mean every boat was — stick to what the chain forces.
The maybes
- MaybeMaybe some canoes seat two and were never inspected.
- MaybeMaybe other outfitters at the lake also own single-seaters.
Why A is right
Chain the repeated term: every kayak is a single-seater, and every single-seater in the fleet was inspected. So every kayak was inspected. The bridge word — 'single-seater' — appears in both facts, and connecting them forces the conclusion.
Why the others are wrong
- BCanoes might seat two or more, and nothing says multi-seat boats were inspected.
- CSome canoes could be single-seaters, in which case they were inspected — you can't rule it out.
- DNothing in the facts compares how urgently different boats needed inspection.
- EThe facts cover Pinecrest's fleet only; other boats at the lake are outside their scope.
Sammy's note
Find the term that repeats across sentences — that's your bridge.
What's a JBDM line?
Just Because Doesn't Mean (JBDM) is the Burton Method's foundational framework for attacking LSAT arguments: identify the premise, identify the conclusion, then say "just because [premise] doesn't mean [conclusion]" and generate "maybes" — alternative explanations that expose the gap between them. That gap is what weaken, flaw, strengthen, and assumption questions all test, so every explanation on this page starts with the JBDM line. It's a micro-lesson in the system, not just an answer key.
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