Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

Spot the cat in the picture below

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

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?

What breaks yet never falls, and what falls yet never breaks?

What Deficiency does the below rebus represent?

VIT_MIN

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"