It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

Who has married many women but was never married?

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

Find the 8 in the below-given Image.

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

Can you solve the below tricky visual equation?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?