You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

When is the top of a mountain similar to a savings account?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

What has no start, end, or centre?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

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?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle: