What do you get if you add 2 to 100 four times?

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

What is full of holes but still holds water?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

How can you take 2 from 5 and leave 4?

Can you count the number of children in the picture below

It's been the first day of the school when a young girl was found raped and murdered.
Police suspect four male teachers as on the killers and ask them what they were doing in the morning in time 8:00 am.
1. Wayne: I was reading the newspaper.
2. Terry: I was checking chemistry papers
3. Bridge: I had locked myself in my room as my wife left me.
4. Cole: I dropped my wife to her office.

Who is the killer?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

A donkey is behind another donkey
I'm behind that second donkey
But there is a whole nation behind me

It is a murder you can describe in a word.