-
Blue or red? – solution
(Read the problem here) There are 13 blue balls. If we take only one blue ball, the ball will be back to the box. If we take two blu balls, both will be out from the box. It means blue balls can not get out alone. Means there always at least one blue ball in…
-
Heaven or hell – solution
(Read the problem here) The woman should ask to anyone of them “Am I a woman?” If the guard say “Yes”, then she just go to the door, but if the guard say “No”, then she choose the other door. (…just for fun :))
-
Four captives – solution
(Read the problem here) D and C can not see anyone, so it’s impossible for them to have any clue. A can see B and C. Seeing B and C’s hat, A still not getting the answer, so A can not say anything. B only can see C. But if B has the…
-
Four captives
Andy, Brian, Celine, and Drake were captivated by a very bad person and were positioned as what can be seen in the picture below. All of them face a wall. Each of them was given a hat. No one of the four knows the colour of the hat that is worn by themselves, but they know that…