What occurs twice in a week, once in a year but never in a day?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

You are given 2 eggs.
You have access to a 100-storey building.
Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100th floor, Both eggs are identical.
You need to figure out the highest floor of a 100-storey building an egg can be dropped without breaking.
Now the question is how many drops you need to make. You are allowed to break 2 eggs in the process

In a kingdom, King George did not allow any citizen to visit the world outside. Also, only a person with proper paperwork was allowed to enter or he was sent back. A wooden bridge was what connected the kingdom to the world. The king had appointed a sharpshooter who would check the every five minutes on the bridge to check. After checking, he would go back to his hut and return exactly after five minutes again. The bridge took 9 minutes to cross.

A merchant was able to escape the kingdom without harming the shooter. How?

I am a mother. However, I never give birth.

I am a father. However, I never nurse my children.

Wandering is not possible for me, but standing still happens occurs rarely.

Who am I?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

Prove that twice of ten is the same as twice of eleven.

John is the son of Jacob.
So,
Jacob is the_____of John's father?

What is so fragile that saying its name breaks it?

Which Travels Faster? Solve below famous picture riddle: