2014 AMC 10B Problem 18
Problem 18 of 25IntermediateAlgebra
A list of positive integers has a mean of a median of and a unique mode of What is the largest possible value of an integer in the list?
Answer choices
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Solution
The list has total sum . To maximize the largest entry, minimize the sum of the other ten entries.
In nondecreasing order, the sixth entry is , and must be the unique mode. If appears twice, the least possible first ten entries sum to , giving largest entry .
If appears three times, the least possible first ten entries are , with sum , giving largest entry .
If appears four or five times, the least possible sum of the first ten entries is at least , so the largest entry is at most .
Therefore the largest possible entry is , and the correct answer is E .