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

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

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Which Travels Faster? Solve below famous picture riddle:

At the local model boat club, four friends were talking about their boats.

There were a total of eight boats, two in each colour, red, green, blue and yellow. Each friend owned two boats. No friend had two boats of the same colour.

Alan didn't have a yellow boat. Brian didn't have a red boat but did have a green one. One of the friends had a yellow boat and a blue boat and another friend had a green boat and a blue boat. Charles had a yellow boat. Darren had a blue boat, but didn't have a green one.

Can you work out which friend had which coloured boats?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

Find the missing number in the image below.

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?

A mad serial killer kidnaps people and forces them to play the game of 2 pills with them, In this game, there are pills in the table and one of them is normal pill while the other one is deadly poisonous.
The victim will choose one pill and the killer will pick the other pill and both simultaneously will swallow the pill with water.
victim dies every time.

One day the serial killer kidnaps the Joseph and forces him to play the same game with him.

Joseph solves the mystery of the two pills and remains alive.

Explain?

Which is heavier: a ton of bricks or a ton of feathers?