How can you make number one disappear by adding something to it?

Manish and Manoj play 5 games of chess.
Both Manish and Manoj win the exact same number of games. There is no tie at all.

How?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

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

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

No one wants to have it, but if one got it, he does not want to lose it. What is It?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

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

Can you convert the number zero(0) into a positive number using just one mathematical operator ?