011 235 Sequence

011 235 813 213 ???

What comes next?

455. The numbers are from the Fibonacci sequence in groups of 3. The next numbers in the series are 34 (the 3 was already used in 213) and 55.

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I Am Worthless

I am worthless, yet when added to others I add worth.
I confounded the ancient Greeks, yet I changed men’s understanding.

What am I?

0 (Zero).

Zero is nothing, yet when you add zeroes to a number like 1, it becomes 10, 100 or 1,000.

The ancient Greeks did not have a name for zero and did not use a placeholder. They seemed unsure about the status of zero as a number, philosophizing about how nothing could be something. Once zero was added, it allowed for more mathematical understanding.

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Hard Boiled Kiwi Bird Eggs

If you can hard boil a Kiwi bird egg in 20 minutes, how long would it take to hard boil four Kiwi bird eggs?
Note: Kiwi birds are about the size of a chicken, but they lay eggs that are close to the size of an Ostrich egg. So one would assume they must take a long time to hard boil.

20 minutes. You can boil them all at once in a large pot.

Posted in Brain Teasers

The Ages of a Prince and Princess

A princess is as old as the prince will be when the princess is twice the age that the prince was when the princess’s age was half the sum of their present ages.

What are their ages?

This one took a while to figure out and there are numerous valid ways of finding the answer.

Here is the solution I came up with

I created the following table from the riddle:

 CurrentFuturePast
Princessx2z(x+y)/2
Princeyxz

I then created three equations, since the difference in their age will always be the same.
d = the difference in ages
x – y = d
2z – x = d
x/2 + y/2 – z = d

I then created a matrix and solved it using row reduction.

xyz
1-10d
-102d
.5.5-1d

It reduced to:

xyz
1004d
0103d
0015d/2

This means that you can pick any difference you want (an even one presumably because you want integer ages).
Princess age: 4d
Prince age: 3d

Ages that work

PrincessPrince
43
86
1612
2418
3224
4030
4836
5642
6448
7254
8060

To see other solutions check out the comments from when I posted this on my blog.

Posted in Brain Teasers

Silent Military Communication

How could a member of the military communicate silently and without light?

By using braille.

Braille was based on a tactile military code called night writing, developed by Charles Barbier in response to Napoleon’s demand for a means for soldiers to communicate silently at night and without light. In Barbier’s system, sets of 12 embossed dots encoded 36 different sounds. It proved to be too difficult for soldiers to recognize by touch and was rejected by the military.

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I Am Here, I Am There

I am here, I am there
I am burned into the mind of none
I walk on fire and live on ice
My words are meaningless for I talk not
I hate everyone yet fear no one
I have lived for centuries
Yet I have never existed
What am I?

Nothingness.

Posted in Riddles

More Than a Few

Nothing specific,
but more than a few.
This many clustered
together will do.

Bunch. It’s a vague term that means more than a few. And clustered items like bananas, grapes or celery come in bunches.

By Sef Daystrom

Posted in Riddles

Old Mother Hubbard’s Seven Letters

What seven letters did Old Mother Hubbard use when she opened her cupboard?

O I C U R M T

(Oh, I see you are empty)

Posted in Riddles

You Heard Me Before

You heard me before,
Yet you hear me again,
Then I die,
‘Till you call me again.

An echo.

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Fill With Empty Hands

What do you fill with empty hands?

Gloves.

Posted in Riddles