Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

Two friends were betting. One said to the other, "The coin will be flipped twenty times and each time the coin lands on the head, I will give you $2 and each time it lands on the tale, you will give me $3." After flipping the coin twenty times not a single penny was exchanged among them.

How many times did the coin land on heads?

Can you place six X (crosses) in below board without making three in a row in any way ?

This is a picture puzzle. You have to guess the name of the movie that can be related to the picture.

Can you count the number of triangles in the given figure?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Which of the below owl is odd one out?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?