what does this picture(rebus) riddle means ?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

The husband and wife were jogging in the morning. To match every two steps of the husband, the wife required three steps. If Both of them start with the here right foot. After how many steps do their left foot be together?

What is black when you buy it, red when you use it, and gray when you throw it away?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Can you find the key in the picture below?