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

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

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

You are in a room with no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify which one is a magnet?

Dwayne Johnson was running away with the loot from a heist in his car along with Vin Diesel. One tire was punctured and he dropped down to replace it. While changing the wheel, he dropped the four nuts that were holding the wheel and they fell into a drain. Vin Diesel gave him an idea using which they were able to drive till the rendezvous point.

What was the idea ?

10+10 and 11+11 can give you the same answer.

Explain how?

Count the number of triangles in the picture below:

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

Which number should replace the question mark?