A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

A man desired to get into his work building, however he had forgotten his code.
However, he did recollect five pieces of information
* Fifth number + Third number = 14
* The fourth number is one more than the second number.
* The first number is one less than twice the second number.
* The second number and the third number equals 10.
* The sum of all five numbers is 30.

What is the code ?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

I organized a small get together at my home.
In the party , i have a barrel with some whiskey in it.

Suddenly Guest 1 say 'I bet this barrel of whiskey is more than half full'.
'No, it's less than half full' Guest 2 replied.

I don't have any measuring instrument and without removing whiskey from it , how can i determine which of the guest is right ?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

Can you find the company name in the pictogram below?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

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