The Twelve-coin Problem
A more complex version exists where there are twelve coins, eleven of which are identical and one of which is different, but it is not known whether it is heavier or lighter than the others. This time the balance may be used three times to isolate the unique coin and determine its weight relative to the others.
Read more about this topic: Balance Puzzle
Famous quotes containing the word problem:
“The problem ... is emblematic of what hasn’t changed during the equal opportunity revolution of the last 20 years. Doors opened; opportunities evolved. Law, institutions, corporations moved forward. But many minds did not.”
—Anna Quindlen (b. 1952)