Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

What goes through cities and fields, but never moves?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

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?

Remove two matchsticks to make the below equation correct.

I am lying and I always lie. Tell me whether I am lying or telling the truth.

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?