A frined of mine likes sweets. To be precise, he likes sweets of different tastes. Once he bought four sweets, two strawberry and two lemon.
- How many sweets will you eat? I asked.
- Just two. And I hope they are of different taste.
- Well, they may be, you know. If you are lucky.
- What do you mean?
- Well, if you pick two sweets at random there are 4 possible ways of doing it, and 2 of these have different tastes.
- So you are saying that my chances are 1/2?
- I have found a better way!
- I eat one sweet, it doesn’t matter which.
- And then?
- Of the three remaining sweets 2 have a different taste than the first so my chances are 2/3 for getting two sweets of different taste.
- You must be a genius. I thought 1/2 was all you could hope for.
Problem source: Activa sus neurona by laberintos e infinitos.