What is more useful when it is broken?

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

If eleven plus two equals one, what does nine plus five equal?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Spot 5 differences in two Christmas tree below:

I am a ten letters word
The first four letters have the power to rule,
Next, four-letter can be eaten.
The next three-letter represents a lady.
I can fly as well

what am I looking for?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?