Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

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?

What is harder to catch the faster you run?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Next Number in the Series,

5, 16, 49, 104, ?

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

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

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?

Can you fill the blank with the correct number?

6 30 870 756030 _____

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?