You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Queen Elizabeth organised a royal party.

To Avoid uninvited guest royal family set a password.
Jack (an uninvited person) plan to enter the party. He stand nearby the door.

First guest comes, the security person said 'twelve' and guest replied with six.
Second guest comes , the security person said 'six' and guest replied with 'three'.

Jack thought is enough and he walked to the entry point. The security person said 'eight' , Jack replied smilingly 'four'.
He was immediately thrown out of the party. why ?

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?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

What is the largest number you can write with just 3 digits?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What can you catch but never throw?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?