Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

What type of tree can I carry in my hand?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Why is Saturday stronger than Monday?