How can you drop a raw egg from a height onto a concrete floor without cracking it?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

Prove that the below maths equation is true.

8 + 8 = 91

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

After a heavy Thanksgiving meal, the night watchman went to work. In the morning, he told his boss he had dreamed that a saboteur planted a bomb in the factory and that he felt it was a warning. The boss promptly fired him. Worker confused, Why boss fire him?

What number when divided in half becomes zero?

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?

Alex is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alex survive the fire? (There are no buckets or any other means to put out the fire)