Why Aeroplane windows are round?

In the four images below, can you find the odd one out?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

I look at you, you look at me I raise my right, you raise your left. What am I?

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

Why is the Hole below a Lock?

You were playing ping pong with your friend. Suddenly the ball fell into a narrow metal pipe that was imbedded in the concrete surface of the floor one foot deep. Now you don't have any other ball and you desperately want to take it out and play. You and your friend have your shoelaces, your tennis paddle and a plastic water bottle. However, the bottle cannot fit into the pipe.

How will you take the ball out?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

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