> riddle-Who can solve this

3 men were abducted by aliens. After anal probing them the commander was willing to return them to earth so he took them to the transport bay. Before returning them home they first had to pass a test. He put one collar on each of their necks (he had 3 Green and 2 yellow, so 2 of the collars weren’t used, the prisoners were told this). He then put them in a line so each man could see the collar of the person standing in front of him the first one could see no collars, the second could see one, and the third could see the two collars worn by the two in front of him). If anyone could identify the color of their collar they would all be sent home. After some time passes one of them was able to identify the color of their collar. What color was his collar and which person in the line was it (front, middle, back)? (You must assume the three men are intelligent and are aware that the other men are intelligent as well).

Good luck