There is a box with 99 white balls and 101 black balls in it. And you have a lot of white and black balls outside the box. 

You pick two balls at random from the box. If they are a black and a white, you throw the black ball out and put the white ball back in the box. If however, you got two whites or two blacks then you throw both of them out and instead put back a black one from the pile outside.

Now, you keep doing this till you have one ball left in the box.

What color is the ball?

This will knock your socks off. I found this on the internet.

Look at the picture on the top. If you do not believe the rest of the puzzle, take a printout on your printer. Now divide the picture horizontally as the line in the middle shows. Look at the top half. Divide it into two parts as the vertical line shows.

Now exchange the position of the two parts on the top. Keep the lower half as is. You get the picture in the bottom portion.

If you do not believe me, carefully check that the bottom half is exactly the same in both pictures and the top right is exactly the same in the top picture as the top left in the bottom picture and vice versa.

So far so good? Count the number of people in the top picture ….15, right?

Now count the number of people in the bottom picture!

Let me repeat the subject line…

Whoa! What the heck happened? 🙂