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?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

What number divided by 4 is the same as that number minus 4?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

What does this mean?

CCCCCCC

A sundial has the fewest moving parts of any timepiece. Which has the most?

Find the number of squares in the below-given picture.

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?