Four Times Every Week

What happens four times in every week, twice in every month and once in a year?

The letter ‘e’. There are four ‘e’s in ‘every week’, two ‘e’s in ‘every month’ and one ‘e’ in ‘year’.

Posted in Riddles

The Pattern of Numbers

These series follow a pattern.
2 4 8
1 17 476
65 20987 3571890

This series does not follow the pattern
18 79 45

What is the pattern?

The numbers must be in ascending order. This can be a fun one to have people work out in person, as they test out three-number series and you can tell them whether or not they satisfy the pattern.

Thanks to Patrick for sending this in and thanks to this video from Veritasium for inspiring Patrick.

Posted in Brain Teasers

Up and Down and Round About

I’m up and down and round about,
yet all the world can’t find me out.
Though thousands have employed their leisure,
they never yet could find my measure.
I’m found in almost every garden,
In a compass or a farden.
There’s neither chariot coach nor mill
may move one inch except I will.

What am I?

A circle.

Posted in Riddles

What Digit Does Each Letter Represent?

This is what you know:

1. Each letter represents a different digit from 1 to 9
2. The total of each row is 17.
3. (B × B) + B + F = A
4. C × F = EF (a 2-digit number, not their product)

A B C
D E F

What digit does each letter represent?

A = 7
B = 1
C = 9

D = 8
E = 4
F = 5

A + B + C = 17
D + E + F = 17
B2 + B + F = A
C × F = EF

To begin with, B has to be a 1 or 2 or else A wouldn’t be a single digit. Plug in B = 2, gives you 6 + F = A, meaning F and A can only be (1,7) or (3,9). To get 17, C would have to be 8 or 6, but those values don’t work for C × F = EF. So B must be 1.

2 + F = A means F and A can be (2,4), (3,5), (4,6), (5,7), (6,8) or (7,9). To get 17 on the top row, the only option that leaves C as a single digit is F = 5 and A = 7.

C × F = EF
9 × 5 = 45, so E = 4 and D = 8 to make the second row equal to 17.

Posted in Brain Teasers

Dumbstruck Beekeeper

Which word does not belong?

beekeeper, dumbbell, dumbstruck, untruthful

Dumbbell. All of the other words have only one of the vowels (a, e, i, o, u).

Posted in Brain Teasers

No Head On Which A Hat To Place

I always run but never walk,
I sometimes sing but cannot talk,
No head on which a hat to place,
You always look me in the face.

What am I?

A clock. It runs all the time, it “sings” for hourly chimes, cuckoos or alarms, it doesn’t have a head (but does have hands) and you look a clock in the face to tell the time.

Posted in Riddles

A Wonderful Help To Women

I am a wonderful help to women,
The hope of something to come.
I harm no citizen except my slayer.
Rooted I stand on a high bed. I am shaggy below.
Sometimes the beautiful peasant’s daughter, an eager-armed,
Proud woman grabs my body,
Rushes my red skin, holds me hard,
Claims my head. The curly-haired
Woman who catches me fast will feel
Our meeting. Her eye will be wet.

What am I?

An onion. Onions help add flavor to meals, they make the person who cuts them cry and they grow hair downtown.

Posted in Riddles

Dividing Five Diamonds Equally

How can five people divide a bag of five diamonds equally without cutting them while still leaving one diamond remaining in the sack?

Give four of the lucky folks a diamond each, then give the fifth person the bag with the remaining diamond still inside.

Posted in Brain Teasers

What is the Five Digit Number?

What 5-digit number satisfies the following requirements?

1. No zeroes
2. First two digits are the same
3. Fourth digit is twice the first
4. Last digit is twice the third
5. Sum of all digits is 18

33264.

There are several ways of solving this. One way is to represent each spot with a letter, A – E.

Then you have these equations:

A = B
D = 2 * A
E = 2 * C
A + B + C + D + E = 18

By simplifying, you get:

4 * A + 3 * C = 18

Plug in values for A and C to find that A = 3 C = 2.

Posted in Brain Teasers

Four Legs But No Tail

I have four legs but no tail. Usually I am heard only at night. What am I?

A frog. The frog is an amphibian in the order Anura (meaning “tail-less”) and usually makes noises at night during its mating season.

Posted in Riddles