What is the riddle which can be asked all day with a different correct answer each time.

A woman named Maria was at the funeral of her mother. She met a nice young man that she had never seen before and after the service, they spent a bit of time together. Then she got busy and didn’t get his name or phone number before he left. She tried to find him, but no one knew who he was or how to contact him. A few weeks later, Maria’s older sister dies and the police suspect murder. Who killed the sister?

What month of the year has 28 days?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

I have teeth but i don't bite. Who Am I ?

Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

Can you count the number of children in the picture below

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

Alex is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alex survive the fire? (There are no buckets or any other means to put out the fire)