What can go up a chimney down, but can’t go down a chimney up?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

Remove two matchsticks to make the below equation correct.

What does does this rebus picture means ?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

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

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

How many times can you subtract the number 5 from 25?

What is common among 11, 69, and 88?