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

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

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

If you say my name, I will no longer exist. What am I?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

What can jump higher than a building?

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

If Japan and Panama decided to merge into a single country, probably people will name it Japanama.

Can you think of two more such country's unions that could produce similar names like Japanama by overlapping their three letters?

How is the moon similar to a dollar?