You are an expert on paranormal activity and have been hired to locate a spirit haunting an old resort hotel. Strong signs indicate that the spirit lies behind one of four doors. The inscriptions on each door read as follows:

Door A: It's behind B or C
Door B: Its behind A or D
Door C: It's in here
Door D: It's not in here

Your psychic powers have told you three of the inscriptions are false, and one is true. Behind which door will you find the spirit?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?

There is a place where if I stand up straight, I will still be considered sideways.

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

Move three sticks of the spiral below to form a square.

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?