This riddle has been around for some time on internet platforms such as Instagram, Facebook, and WhatsApp, and many people still argue over what the answer might be, as there are many possibilities. The correct answer is Man 2 will shout first. Man 3 and Man 4 will not be able to tell what colour hats they are wearing since they cannot see the other men. Man 1 can see Man 2 and Man 3 but is not able to tell what colour hat he is wearing as Man 2 and Man 3 are wearing different colour hats. So Man 1 will not shout out. Then based on Man 1’s silence, Man 2 is able to interpret that he (Man 2) and Man 3 are wearing different colour hats. Since Man 3 is wearing a black colour hat, so Man 2 knows that he is wearing a white colour hat.