Replace the question mark with the correct number.

What does does this rebus picture means ?

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

What breaks yet never falls, and what falls yet never breaks?

Today is a very icy and cold morning in Newcastle. Mr Shearer, an office bus driver arrived to pick up the employees from the last stop. Shearer suddenly remembers that he needs to pick a newly joined 4miles to the north. Mr Shearer lost his direction compass, a few minutes later Shearer is able to figure that he is moving in the correct direction i.e. north. How did Shearer know that he is moving in the correct direction?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

Can you find the dog hidden in a group of pandas?

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

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?