What has to be broken before you can use it?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

How could a baby fall out of a twenty-story building onto the ground and live?

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

Detective John was investigating a murder in China.
It was a difficult case, and John was completely stumped until he noticed a message sent to him by the killer cunningly hidden in a newspaper advertisement selling Car Licence Plates.
Detective John thought about it for a while, and when he had solved the puzzle, immediately arrested the guilty man.

Q1) How did John know the advert was a clue for him?

Q2) Solve the code and tell me who John arrested.

This is the newspaper advert (Car licence plates for sale) that Detective John saw.

Plates For Sale;

[W 05 NWO]
[H 13 HSR]
[O 05 EBM]
[D 08 UNE]
[U 10 HTY]
[N 04 BRE]
[N 16 TTE]
[I 26 LHC]
[T 10 AEE]
[I 26 CNA]
[X 22 VDA]

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

It is a 5 letter word if you take away first letter it is something you get from sun, if you remove second letter you will get something to eat, if you remove third letter you get a word you use in pointing at and if you remove the fourth letter you get something to drink. What is it?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?