I have created several riddles with my brother, and one of my favourite ones is this one. It is based on the classic prisoner hat riddle, but it has a twist.
TASK: You have to guess which ones are wearing green hats and which ones are wearing black:
DESCRIPTION: A, B and C can see the hats of their two mates, but not their own hat. Pay attention to the order, they give tips one by one:
1- A can see the hats B and C are wearing, but he doesn’t know what hat he’s wearing
2- After listening to A, C figures out which hat he must be wearing. So, C says, "I know my hat now". This statement tells A,B and D that C didn't know his hat color before A spoke but he knows it now, after A has spoken
3- Finally, D, who is hidden behind a wall and can’t see anyone, figures out what hat he is wearing, just by hearing what A and C have said.
You don’t know how many green and black hats there are of each color (4 in total, all of them must be wearing one), but they do know how many hats there are of each color. For example, if B were the only black hat, A would know his hat is green.
We already know B is wearing a black hat. You have to guess A's, C's, and D's hat! There is only one possible solution