Data Analyst Intern

You have 9 balls, equally big, equally heavy - except for one, which is a little heavier.

How would you identify the heavier ball if you could use a pair of balance scales only twice?

How will you measure 4 litre of water from a 3 litre and 5 litre jug? There are no measurement lines on the jug. You can use any amount of water but only those 2 jugs.

1. There is an island with 100 prisoners, all of who have green eyes.
2. All 100 prisoners are perfect logicians.
3. They all want to escape the island.
4. The condition of escaping the island is that one can deduce one’s own eye colour, and tell the guards the answer at midnight. If the answer is correct, the prisoner is set free. Else, he/she is killed.
5. The restrictions are: None of them knows their own eye colour (through mirrors, reflective surfaces or otherwise), and none of them is allowed to communicate with one another through any means whatsoever.
6. However, they can see each other and know everybody else’s eye colour.

You are a guest of the island owner (now called the IO). You want to free all the prisoners. The IO allows you to:

1. Make one and only one statement in the form of an announcement to all prisoners.
2. The statement does not convey any new information.

I was asked to generalize a puzzle for 'n' values from the previous round. 
The puzzle was 

You have 9 balls, equally big, equally heavy - except for one, which is a little heavier.

How would you identify the heavier ball if you could use a pair of balance scales only twice?

This was asked in previous round for '9' balls, I was asked to do it for 'n' balls using my logics.
Paper & Pen were provided.