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Problem 666

AMC 10/12, early questions

Combinatorics Difficulty 3.0 Find the answer UKMT Junior Mathematical Challenge · United Kingdom · 2020

Susan is attending a talk at her son's school. There are $8$ rows of $10$ chairs where $54$ parents are sitting. Susan notices that every parent is either sitting on their own or next to just one other person. What is the largest possible number of adjacent empty chairs in a single row at that talk? (A) $3$ (B) $4$ (C) $5$ (D) $7$ (E) $8$

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