I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Can you find the key in the picture below?

Can you solve the below geography rebus by decoding the below rebus ?

Can you move 2 matchsticks to form four equal sized squares.

How many triangles can you count in the figure given?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

Can you find out the missing number in the grid?

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

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?