A fake among 12 coins
| Topic | Difficulty | Companies |
|---|---|---|
| Algorithmic | MEDIUM | Microsoft Bloomberg Amazon Google |
There are 12 identical-looking coins. One of these coins is counterfeit and is known to be lighter than the genuine coins. What is the minimum number of weighings needed to identify the fake coin with a two-pan balance scale without weights?
The answer is an integer. Just put the number without any decimal places.