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Have a go at this without a calculator....

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magicmerlin | 16:41 Thu 23rd Jul 2009 | Riddles
26 Answers
Imagine that you can fold a piece of paper as many times as you want to (we all know it's about 8 times in reality).

This piece of paper is one thousandth of an inch thick (0.001")

You are to fold this piece of paper exactly in half for 50 times.

What is the total thickness from top to bottom of this piece of folded paper?
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2 ^ 50
and multiply by 0.001"
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So spodo what is your answer...?
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Did you have to tell everybody how to work it out....
it very basic stuff merlin, he's hardly spilling the beans!
Without a calculator somewhere between 1.5 and 2 million miles.
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Rollo, you are closer than I expected you to be but still a long way off. Most people answer with a few feet or miles.
my answer is 1.5 glanghorns
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Spodo. Is there such a thing as a glanghorn or are you taking the p@ss
Loks like I moved a decimal point too far.

Ten times more than my previous answer. Between 15 million and 20 million miles.
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Rollo, it looks like you used a calculator.
1 Glanghorn = slightly more than the thickness of a thin piece of paper folded 49 times, and slightly less than if it is folded 50 times.
I used the law of indicies to work out 2^50, but I made a mistake.
I make it 0.926366E-12 parsecs.
62,137,119 miles and 308 yards - I think.
It's not a seasy as multiplying 2 to the power 50.
There is a formula I'll have to dig out involving π I think
According to this site it's approximately the distance from Earth to the Sun!
http://raju.varghese.org/articles/powers2.html
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factor30. According to your link 115m kilometers = 95m miles. This is wrong, using an approx of 1.6km per mile, 115m km = approx 70m miles. They also use paper thickness of 0.1mm which equals 0.00393", nearly 4 times thickness as my piece.
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The answer to the question is approx 17.76m miles.
I'd work it out like this:
2^10 = 1000 (roughly)
so 2^50 = 1000^5
If the paper was 0.001 mm thick (I have to think in metric) one factor of 1000 would make it 1 mm. Two more factors of 1000 would make it 1 km. We are left with two factors of 1000. So the answer would be 1 million kilometres.
An inch is 25.4mm, increasing the answer to 25.4 million kilometres.

The approximation 2^10 = 1000 is 2.4% too small, so we need to increase the answer by 2.4% five times. This will be a bit more than 12% as it is compounded. Let's guess 12.5% becaue that is one-eighth i.e. about 3.2 million kilometres.

Answer = 25.4 + 3.2 = 28.6 million kilometres.

How did I do?

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