Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

What does an Island and the letter T have in common?

If all the below statements are true

1. Gianni was either in Italy or France in 1997.
2. If Gianni did not kill Versace, Hilton must have killed him.
3. If Versace died of suffocation, then either Gianni killed him or Versace committed suicide.
4. If Gianni was in Italy in 1997, then Gianni did not kill Versace.
5. Versace died of suffocation, but he did not kill himself.

Who killed Versace and where was Gianni in 1997?

Which tank will fill first?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10