Five students — A, B, C, D, E — sit in a row. A must sit next to B. C cannot sit next to D. How many valid arrangements are there?

A 24

B 36

C 48

D 60

✓ Correct Answer: Option B

Treat AB as a unit (2 internal arrangements). 4 units in a row = 4! = 24. Subtract C-next-to-D cases. With AB as a unit, there are 12 arrangements where C is next to D. So 48 - 12 = 36.

💡 Why is B) the correct answer?

The correct answer to the question "Five students — A, B, C, D, E — sit in a row. A must sit next to B. C cannot sit next to D. How many valid arrangements are there?" is Option B: 36.

The other options — A) 24, C) 48, D) 60 — are incorrect for this LSAT Exam Prep question. As explained above: Treat AB as a unit (2 internal arrangements). 4 units in a row = 4! = 24. Subtract C-next-to-D cases. With AB as a unit, there are 12 arrangements where C is next to D. So 48 - 12 = 36.

📚 About This LSAT Exam Prep Practice Question

This 4-level LSAT Exam Prep question from the Analytical Reasoning topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free LSAT Exam Prep practice test or use flashcards for spaced repetition review.

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Five students — A, B, C, D, E — sit in a row. A must sit next to B. C cannot sit next to D. How many valid arrangements are there?

✓ Correct Answer: Option B

📚 About This LSAT Exam Prep Practice Question

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