Answer:
The Hotel Manager put the first two guys in room number 1. The two sons ... But you have only 2 rooms with an even number of doors, the others have 5 doors. . 30. ... Door 4 : A Desert in which the hot blazing sun will burn you instantly

Sentence is a group of words which makes a complete sense.
YES, SOME IDEAS CAN BE ELUSIVE, BECAUSE YOU MIGHT HAVE THOUGHT ABOUT IT THEN FORGOT THE NEXT DAY. HOWEVER THE MORE YOU BEGAN TO ORGANIZE AND THINK ABOUT THIS IDEA, IT'S EASY NOW WHEN YOU GET TO ACTION.