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

I am 5 letters long.
My first two tell you who I am
My first 3 could be a medicine
My last three reversed could be a young boy.
My 4th, 3rd and 2nd in that order could be a fruit drink.
If you have me you may hang me round your neck
WHAT AM I ?

A Detective reviewed the information they had on the case so far.

A lady named 'Caterina' was found shot and they already had a list of suspects - Ankit, Tarun, Harish, Manoj and Manish.
The killer is a fan of challenges him by leaving notes ad various places.
* The first was found in a toilet room.
* The second was found in an art room.
* The third was in a restroom.
* the fourth in an underwater room.
* The fifth at the no-smoking room.

All of the notes read the same thing, 'The clues are where you find the notes.' Yet, nothing was found at any place the notes were.
Detective the genius, immediately solved the case.
Who was the killer?

What goes up but never comes down?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

How many bananas can you eat if your stomach is empty?

I taste better than I can smell. Who am I?

Count the number of balls in picture below:

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

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?