If two's company, and three's a crowd, then whats four and five ?

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

Which is faster, Heat or Cold ? Explain.

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

I can write cow in 13 letters.

Can You?

Take number 1000 and then add 20 to it.
Now add 1000 one more time.
Now add 30.
Now add 1000 one more time.
Now add 40.
Now add 1000 one more time.
Now add 10.

What is the total?

What type of tree can I carry in my hand?

Which part of London exists in France as well ?

Different lights make me strange by changing me into different sizes. What am I?