The how many are in the bedroom riddle is a classic brain teaser that dates back to the 18th century. The answer is zero, as there aren't actually any people in the bedroom. This riddle relies on double meaning and wordplay to trick your mind into thinking it must be something else, because there isn't an obvious answer at first glance. It's a good example of lateral thinking, which is when you approach a problem from an unexpected angle or viewpoint and come up with creative solutions.