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

This was asked in an interview with Coa-Cola.

The interviewer has given me 100 marbles(50 white and 50 black) and two empty boxes.
He then told me that he will leave the room and i need to place all the marbles in two boxes.

And When he come back, he will draw a marble from any of the two box and if the marble is white I will be hired.

Also
* No box can be empty.
* All 100 marbles must be placed in one of the two boxes.

So what should I have done?

A and B have a certain number of chocolates with them. If B gives one chocolate to A, they will have an equal number of chocolates. But if A gives one chocolate to B, then A will be left with half the number of chocolates that B has.

Can you find out the number of chocolates they have right now?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Can you name an animal whose killing cannot be performed without spilling your own blood?

How many Watermelons are there in the below picture?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

A woman who works in a sweet shop has a measurement of 32-26-36, is 5"4" tall, and wears size "6" shoes. What do you think she weighs?

Can you solve the maths in the below-given picture equation?