Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

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?

A worker is to perform work for you for seven straight days. In return for his work, you will pay him 1/7th of a bar of gold per day. The worker requires a daily payment of 1/7th of the bar of gold. What and where are the fewest number of cuts to the bar of gold that will allow you to pay him 1/7th each day?

Where do fish keep their money?

What English word has three consecutive double letters?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

Can you spot the hidden girl in the picture below?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

who is silent in the parliament?