There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

What has a bottom at the top?

You have a thousand Re. 1 coins with you. You have ten bags with you and you can put any number of coins in each of the bags. The condition is that if someone asks you for any amount between 1 and 1000, you must be able to give that amount by just giving the bag (you are not allowed to open the bag and give coins).

How will you do 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?

What can you see in the middle of March and April that you can never see in any other month?

A woman lives in a Tall building thirty-six floors high and served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

What is always in front of you but can’t be seen?