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

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

Which tank will fill first?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

I look at you, you look at me I raise my right, you raise your left. What am I?

At a party, there are five people and a whole round cake lying at the centre of the table. Only four people will make a cut and take their piece and the last one will get the remaining piece on the table. How can they make sure that everyone gets a 1/5th of the piece?

To attend world science seminar, A famous chemist from Mexico visit
London. In the lab, the scientist was killed and his six assistants were under suspicion of killing the chemist.
Name of six assistants: Austin, Wayne, Dege, Oscaru, Lingard, and Rojo.
He left a note "76-20-44 79-16-22-7"

A local detective Jack was called to solve the case,

After reading the note, Jack instantly asked the police to arrest the murderers.

Who are the murderers?

A car is crossing a 20 km-long bridge. The bridge can support at most 1500kg of weight over it. If somehow, the weight on the bridge becomes more than that, it will break.

Now, the weight of the car is exactly 1500kg. At the midway, a bird comes and sits on the roof of the car. This bird weighs exactly 200 grams.
Can you tell if the bridge breaks at this point or not?

No matter how little or how much you use me, you change me every month. What am I?

Can you find out the total number of triangles in the given figure?

What's a single-digit number with no value?