Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

Can you solve the equation by finding the value of
A) Horse
B) Cowboy boot
C) Horseshoe

In the Picture?

John was piloting a plane behind a car but was never able to overtake it. Why?

Can you find the mistake in the below statement?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

Two fathers and two sons went fishing one day. They were there the whole day and only caught 3 fish. One father said, that is enough for all of us, we will have one each. How can this be possible?

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

Christina is older than Kareena and Karishma. Katrina is older than Karishma and younger than Kareena. If Kareena has a brother named John, who is older than Christina, who's the youngest?

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?