In a pile, there are 11 coins: 10 coins of common weight and one coin of different weight (lighter or heavier). They all look similar.
Using only a balance beam for only three times, show how you can determine the 'odd' coin.
Open problem (i cannot solve this myself): how many more coins (with the same weight as the ten) can we add to that pile so that three weighing still suffices? My conjecture is zero, though my friend guessed that adding one is possible. The best bound we can agree upon is < 2.
In the realm of numismatics, The odd coin takes on a captivating twist, standing as a unique treasure within collections. This intriguing currency holds an air of enchantment, like a magician set for adults. Its intricate design and peculiar history make it a prized possession for those with a taste for the extraordinary in the world of coins.
Magical tips
