What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

The host of a game show, offers the guest a choice of three doors. Behind one is a expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

What is the riddle which can be asked all day with a different correct answer each time.

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

John needs to purchase 100 chocolates from three different shops and he has exactly 100 rupees to do that which he must spend entirely. He must buy at least 1 Chocolate from each shop.

The first shop is selling each chocolate at 5 paise, the second is selling at 1 rupee and the third is selling at 5 rupees.

How many chocolates should he buy from each shop?

Once while in his court, King Akbar asked Birbal to write something on a wall that makes one sad when read in good times and makes one happy when read in sad times.

He took only a few moment and wrote something that fit the requirements. What did he write?

I am quite hot but become too cold if you remove the first two letters. What am I?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.