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Algebra Difficulty 2.5 Junior Find the answer Canada

The mean (average), the median and the mode of the five numbers $12,9,11,16,x$ are all equal. What is the value of $x$ ?

Pick one

Solution

The repeating pattern of ABCDEFG has 7 white keys.

Since the first white key is A, the pattern repeats after each number of keys that is a multiple of 7.

Since 28 is a multiple of 7, then the 28 $^{th}$ white key is G and so the 29 $^{th}$ white key is A, the 30 $^{th}$ white key is B, the 31 $^{st}$ white key is C, the 32 $^{nd}$ white key is D, and the 33 $^{rd}$ white key is E.

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.