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

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

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

During an interview, the interviewer ordered hot coffee for the candidate to relieve the stress. The coffee was kept before him. After a minute, the interviewer asked him, 'What is before you?' He replied 'Tea'.

The candidate was selected immediately. Why?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

What demands an answer, but asks no questions

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

In the attached figure, you can see a chessboard and two rooks placed on the chess board. What you have to find is the number of squares that do not contain the rooks. How many are there?

What does below Rebus say?

XLR8

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?