Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Find out which of the given views in the picture is accurately the top view of the given pyramid.

What is full of holes but still holds water?

What is at the end of a rainbow?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

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

You are in a land where thirty men and two women were dressed in classic black and white dresses.
They begin to fight as soon as any of them move.

Where are you?

A man embarked on a questionnaire game. He kept asking the same question to whomever he found. The answer each time was different.

Can you guess what the question was?

How can you make number one disappear by adding something to it?

If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?