What is the next shape from answers A, B, C, and D figure?

Can you replace the question mark with the correct number in the below table sequence?

What is black when you buy it, red when you use it, and gray when you throw it away?

You can find some missing letters in the picture. By placing two particular letters in the spaces, you can form a nine lettered word beginning from one of the corners and going clockwise direction to the middle. Can you find out the letters and the word?

Find the next number in the series.
1 10 24 43 67 ?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb?