The White Grinder Riddle

I’m white, and used for cutting and grinding. When I’m damaged, humans usually remove me or fill me. For most animals, I am a useful tool. What am I?

A tooth.

The Doubling Tree Riddle

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

9 years.

Explanation:

The tree doubles in height each year.
In 10 years, it reaches full height.
This means that one year before reaching full height, it must have been half of its maximum height.
So, at year 9, the tree was half of its final height before doubling in its 10th year.

The Twin Logic Puzzle

You walk up to a mountain that has two paths. One leads to the other side of the mountain, and the other will get you lost forever. Two twins know the path that leads to the other side. You can ask them each only one question. Except! One lies and one tells the truth, and you don’t know which is which. So, What do you ask?

You ask one twin, “Are you twins?”. If he says “Yes”, he is telling the truth. Therefore, you ask the other twin which way to go and go the opposite way because he is lying. If he says “No”, he is the liar and you ask the other twin which way to go because he is telling the truth.

The Climbing Mystery Riddle

I have no feet, no hands, no wings, but I climb to the sky. What am I?

Smoke.

The Missing “A” Riddle

How high would you have to count before you would use the letter “A” in the English language spelling of a whole number?

One thousand.

In the English language, numbers from one to nine hundred ninety-nine do not contain the letter “A” when spelled out. The first occurrence of “A” appears in “one thousand.”

The Anagram Riddle

Test Mars. What is the anagrammed word?

Smartest

The Barrel Riddle

A man takes a barrel that weighs 20 pounds and then puts something in it. It now weighs less than 20 pounds. What did he put in the barrel?

A hole.

The Bright Mystery Riddle

What brightens your day when it’s dark, although it’s usually in the shade?

A lamp.

A Is The Father Of B

A is the father of B. But B isn’t the son of A. How is this possible?

B is the daughter of A.

The Green Door Riddle

Your friend invites you to a party and says you have to bring something to get through the green door. You can bring a poodle but not a dog, a stool but not a chair, and a rabbit but not a hare. What is the pattern for the things you can bring?

You can only bring things with double letters in their spelling.