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

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

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

Can you decipher the two rows to find the hidden word?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Which word does the below Plexor means ?

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

Can you find the company name in the pictogram below?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?