Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

A person is found murdered in his Chamber. When the crime scene is investigated, the Investigator find out that there is a calendar on which the victim has written a few numbers with his blood. The numbers are 4, 11, 11 and 4.

There are four suspects in the murder, John, Jacob, Anna and Lee. Can you find out who is the murderer?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

In the picture given below, can you find out which digit will take place of the question mark?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

Rahul decided to meet Simran so he boards a local train from Bombay station. Just after the station, there is a 1km long tunnel. The train starts and is now accelerating. Rahul is a claustrophobic guy, so what is the best position for him to sit?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

What has 88 keys?

You bought me for dinner but never eat me. What am I?

Can you spot the hidden girl in the picture below?