Can you replace the question mark with the correct number?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

You’re out on the water and see a boat filled with people. You look away for a second and look back again, but this time you don’t see a single person on the boat. Why? Hint: The boat did not sink.

What is both possible and impossible at the same time?

I have feet, but no legs. Which animal Am I?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

A clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

These types of puzzles are known as charades. What you have to do is to find two words that are referred to in the first stanza and the second stanza and put them together to form the third word in the third stanza.

Just for example, if my first refers to 'off' and my second refers to 'ice', then my whole will be the 'office'.

My first is present - future's past -
A time in which your lot is cast.

My second is my first of space
Defining people's present place.

My whole describes a lack of site -
A place without length, breadth, or height.