Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

How many triangles can you find in this given picture?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

What jumps when it walks and sits when it stands?

When we see 2 but call 10?

It belongs to you, but other people use it more than you do. What is it?

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?