He had a blue dot. If there were only three of them and 2 colors of dot, then his would have to be blue.

At least one of the dots has to be blue, and one has to be red. With the other two dots being red, that would leave his to be the other color, blue.

Okay first there can be 3 blue dots or 3 blue dots, there can be 2 red or 2 blue. There doesn't have to be at least one blue. Okay for the hint look at it from another persons perspective and use process of elimination for what color his dot is. Also remember these are masters of logic!

they all rised up there hand which means they all saw a red dot it doesn't have to be on the forehead the riddle didnt state that it just said if you see a red dot so his answer for red was right

I thought about it some more.

Let's label each of them X, Y, and Z.

X sees two red dots. He thinks that Y might have raised hand seeing Z's forehead, and Z might have raised the hand seeing Y's forehead.
Same thought would have made Y and Z also silent.

Now, Let's assume X answered correctly and his clever. Below is how he came to that conclusion.

He knows that no one is ready to answer. If the mark on his forehead was blue, then Y would see just the red mark on Z, and Z would see the red mark only on Y. In that case, either Y or Z would have confidently said that the mark on their forehead was red because Y would see that X's is blue and Z's is red (since there has to be at least 2 red marks for all of them to raise their hands). Z would not have raised his hand if the mark on Y was blue. Same happens with Z. Since they remained silent and didn't answer, X concluded that the mark on his forehead was not blue. So he answered "red" and was correct.

Yaaaaaaaay perfect explanation! (Im really happy someone got it right!) here is your egg: https://www.sylestia.com/view/pets/?petid=4170206

Thanks!

can I be pinged when you have new riddles?

Of course!

thanks

Riddle 3: What has keys but no lock, you can enter but cant leave, has space but no room?

Prize (Purebred Blue Heaven Hydrangea Luffox):