81 x 9 = 801. What must you do to make the this equation true?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

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

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

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

What English word has three consecutive double letters?

Rihana, Peeta, and Logan order a pizza for $10. Out of the three, Rihana and Peeta were quite hungry and ate 6 slices a piece, while Logan had just 2 slices.

Now, they want to split the cost among them fairly but due to the lack of change, they decide to round off the cost to the nearest possible dollar.

Can you find out the fairway which should be used to split the money?

What if the pizza was worth $11?

Give it food and it will live; give it water and it will die.

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

A girl was standing near the window thinking something. All of a sudden she decides something and throws something out of the window. She dies very soon after throwing it. She was perfectly healthy and had no disease or allergy. No one killed her and she did not commit suicide.

Can you think of any possible explanation that is logical as well for what happened there?