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UKMT Pink Kangaroo, 2015

Algebra Difficulty 3.0 AMC 10/12 Find the answer United Kingdom

When one number was removed from the set of positive integers from 1 to $n$ , inclusive, the mean of the remaining numbers was 4.75. What number was eliminated?

(A) $5$ (B) $7$ (C) $8$ (D) $9$ (E) impossible to determine

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