Door 97
All eight kids agree that one house is suspicious, but none of them can quite remember the house number. You collect their statements, realizing that one of them ate some of the candy and is lying,
Which house do you invetsigate?
When I came up to the door, I was greeted with a smile
Two other houses in the neighbourhood have the exact same doormat.
It seemed like a friendly house. They kept the light on.
Answer
Examine the statements to find contradictions
Two statements in direct opposition can't be true at the same time, so you know it is one of those
Only one kid has access to candy
Headless horseman - non-smiling jack-o-lantern on the doorstep (3 of these)
Mummy - must have a doormat (set of 3)
Skeleton - porch lights are turned off
Witch - Note must be less than 3 words
Vampire - No door knocker
Ghost - No doorbell
Frankensteins monster - No spiders web
Mad scientist - Prime house number
Thief lives at number 6