Questions tagged [calculation-puzzle]
A puzzle that involves numerical calculations, such as multiplication and addition. Use with the [mathematics] tag.
1,270 questions
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How can 64 = 65?
Here is a interesting picture with two arrangements of four shapes.
How can they make a different area with the same shapes?
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A camel transporting bananas
A somewhat well-known puzzle is described as such:
You have a pile of 3,000 bananas. You wish to transport them to a place 1,000 miles away on the back of a camel; however, the camel can only carry ...
user88
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The mother of all age-of-the-captain riddles
A few days ago, as I was delving into the mess in my grand parents' attic, I found an impressive ancient book that was written in a language that I had never seen before.
"This book is a collection ...
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Making π from 1 2 3 4 5 6 7 8 9 [closed]
There have been two other questions here and here that are similar to this one, but this changes the rules up a little.
Your job is to approximate $\pi$ using the sequence of digits (in order):
1 2 3 ...
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XOR - Is it possible to get a, b, c from a⊕b, b⊕c, a⊕c?
Just got a simple question from a friend; still thinking. Let's share it!
Is it possible to get a, b, c when you have a⊕b, b⊕c, a⊕c ?
where ⊕ is the boolean ...
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Can you explain these equations?
Anthony just got a new drone with an HD camera and microphone, and he is eager to test it out. He connects his computer to its wireless live video stream, opens up his window, and flies it outside. ...
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The Cucumber Paradox
Suppose you have 100 lbs of cucumbers and these cucumbers consist of 99% water. You decide to leave the cucumbers in the sun for a while until they consist of 98% water. You bring the cucumbers back ...
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I don't know the two numbers... but now I do
Two perfect logicians, Summer and Proctor, are told that integers 𝑥 and 𝑦 have been chosen such that 1 < 𝑥 < 𝑦 and 𝑥 + 𝑦 < 100. Summer is given the value 𝑥 + 𝑦 and Proctor is given ...
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Self-referential Sudoku
I built this a while back but never had a good forum for it; this seems like the perfect spot to turn it loose. This is a 'traditional' Sudoku; cells are filled with numbers from 1 through 9, and all ...
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Where is Jennifer's husband?
Jennifer is 21 years older than her son Douglas.
6 years from now, Jennifer will be 5 times as old as Douglas.
Question: Where is Jennifer's husband most likely to be right now?
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1 2 3 4 5 6 7 8 9 = 100
The sequence of numbers $1\ 2\ 3\ 4\ 5\ 6\ 7\ 8\ 9$ has the property that you can insert mathematical operators in between the numbers from $1$ to $9$ and make the expression evaluate to 100. For ...
anon
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A strange operator on my new calculator
Yesterday, I bought a new calculator in an antique shop. I wanted to try some basic operations to see if it was working well. Everything felt right, except for the + sign: it seemed like it was ...
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Find average age without revealing your age
Ana, Barbara, Carol and Diana want to know their average age. But no lady wants to disclose her age.
They decide a strategy and use a calculator (one that doesn't store steps) and tapped some keys ...
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9-5=5? Matchstick problem
Move one matchstick to make an equality.
Question made by me (Is this too easy?)
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2 vs. 1.005^200
Without using a calculator or a computer can you determine which of these two numbers is bigger: 2 or 1.005200 ?
I saw this puzzle in a YouTube video, which I will post later.
