What do you answer even though it never asks you questions?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

Which flower has two lips?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

My thunder comes before lightning.
My lightning comes before my rain.
My rain dries up all the land it touches.

Who am I?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

There is an exact a week gap between Christmas and New Year. Hence, It is obvious that the new year that comes right after Christmas comes on the same day of the week.

A Strange thing happened in the Year 1777. Christmas occurs on Wednesday and New Year on Monday. How is that possible?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _