What does it mean?

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

What has to be broken before you can use it?

Find the missing number in the image below.

If a wheel has 54 spokes, how many spaces are there between the spokes?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

Can you write down eight eights so that they add up to one thousand?

A sundial has the fewest moving parts of any timepiece. Which has the most?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.