A Special Something Shared

The numbers 3, 7, 8, 40, 50 and 60 all share something that no other whole number does. What is it?

When spelled out in English they each have exactly five letters.

Posted in Brain Teasers

A Seed of Three Letters

I am a seed, three letters in the name,
Take away two and I sound quite the same.

What am I?

Pea.

Posted in Riddles

A Special Racecar

What is special about the phrase “Race car”?

It’s a palindrome (a word or phrase that’s spelled the same backwards and forwards).

Posted in Brain Teasers

Cheap To Make, Easy To Define

I’m cheap to make and easy to define.
A riverbank could populate the line.

What am I?

A boundary.

By Sef Daystrom

Posted in Riddles

A Four Word Admonition

What four word admonition makes the happy person sad and the sad person happy?

The phrase, “This too shall pass.” According to Wikipedia, the well-known phrase is often attached to a fable of a great king who is humbled by these words, and to someone who is experiencing something wonderful, it can be saddening. But to one who is in the pits of despair, it is a phrase that brings relief and hope.

In other words, if a happy person is told, “This too shall pass” it will make them sad. But to a person on hard times, hearing, “This too shall pass” will cheer them up.

Posted in Riddles

A Synonym of Drag

I’m a five letter word. Remove my last two letters and I’m a synonym of drag. My second and third letters form an exclamation and my first and second letters are a homophone with a number. What am I?

Towel. Tow is a synonym of drag, ow is an exclamation when you’re hurt (and far more appropriate in mixed company than the four-letter alternatives) and to is a homophone of two.

Posted in Riddles

False Positive HIV Test

Imagine an HIV test that is 95% accurate (false positive rate of 5%) and around 2% of the tested population is infected with HIV. What is the probability that you actually have HIV when your test comes back positive?

29%

To read more about this, see the False Positive Paradox page on Wikipedia.

Posted in Brain Teasers

Sever Bones and Marrow

My first is in wield, sever bones and marrow.
My second is in blade, forged in cold steel.
My third is in arbalest, and also in arrows.
My fourth is in power, plunged through a shield.
My fifth is in honor, and also in vows
My last will put an end to it all.

What am I?

Weapon

Posted in Riddles

Counting Squares

How many squares of any size are in this grid?

4 x 4 grid

30.

There are:

16 1×1 squares
9 2×2 squares
4 3×3 squares
1 4×4 square (the whole shape)

Hence, 16 + 9 + 4 + 1 = 30.

Posted in Brain Teasers

I Live in Water

I live in water
If you cut my head I’m at your door,
If you cut my tail I’m fruit,
If you cut both I’m with you

What am I?

A pearl. They’re found underwater. Removing the head (p) leaves Earl, a guy who could be at your door. Removing the tail (l) leaves pear, a fruit and if you cut both off you’re left with ear, which is with you because it’s attached to your head.

Posted in Riddles