What number when divided in half becomes zero?

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

There are two insects on a tile. Insect X is sitting on one side of the tile (point A) and Insect Y is sitting opposite on the other side of the tile (point B). Now both of them decide to change their position and thus X starts crawling to point B and Y starts crawling to point A. When they meet and pass each other in between, X takes 20 seconds to reach B and Y takes just 5 seconds to reach A.

Can you calculate the total time each of the insects took to change their positions?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

I always drive my customer away.

Who am I?

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

Which city is three-fifths chick two third cat and 50% goat?

One night, a man runs away from home. He turns left and keeps running. After some time he turns left again and keeps running. Later, he turns left one more time and runs back home—but when he gets home, he finds a man in a mask. Who was the man in the mask?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?