Why is 6 afraid of 7?

Can you identify the hidden rebus in the image below?

During which month do people sleep the least?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

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

The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?

What has no start, end, or centre?

Until it is measured, not known. Yet how you miss it when it has gone. What is 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 Child was born in Lahore, Pakistan. Still, the child is not a Pakistani citizen. why?