THE 12 COIN PROBLEM – A Brain Teaser

IF one had 12 seemingly identical coins, with 11 being of the exact same weight and 1 being either heavier or lighter than the other 11,

THEN using only a balance, not a scale, and with only 3 measurements allowed, how could one determine which of these 12 seemingly identical coins is different and whether it is heavier or lighter than the other 11?

See if you can solve this problem
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