I am white when I am dirty, and black when I am clean. What am I?

What does a man do only once in his lifetime, but women do once a year after they are 29?

Our product and our sum always give the same answer. Who are we?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

With the help clues provided in the image, can you find the 5 digit key?

What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.