Find out the missing number in the picture attached:

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

A man fell off a smuggling boat into deep water. He could not swim and he was not wearing anything to keep him afloat. It took 30 minutes for the people on the boat to realize someone was missing. The missing man was rescued two hours later on the return trip. Why didn't he drown? Note:- He didn't know swimming, the sea was deep, and He wasn't holding anything

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?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Can you find out the remainder when 3^300 is divided by 5?

Find the missing number in the sequence below:

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

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

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?