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Topic: Live action maths debating... (Read 334 times) |
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Noke Lieu
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pen... paper... let's go! (and bit of plastic)
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Live action maths debating...
« on: Jul 9th, 2009, 5:54am » |
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A man buys a horse for $20.
He sells the horse for $30.
He buys it back for $40.
He sells it for $50
Did he make money, or lose money? DId he break even? If he did make money, how much did he make? If he lost how much did he lose?
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Now, I'm not really asking such a question here. It's something that I picked up listening to a podcast on 'maths anxiety'.
I recently asked a bunch of not-particularly-mathsy-types this question and then watch them dissect it and fold it and trap them selves up in their own thinking.
It was awesome to see it in action.
Don't give them the answer.
Have a try. You might like to mention what you observe?
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a shade of wit and the art of farce.
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towr
wu::riddles Moderator
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Some people are average, some are just mean.
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Re: Live action maths debating...
« Reply #1 on: Jul 9th, 2009, 6:46am » |
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There is something to be said for the perspective that because of the second step he lost $10. Just a rearrangement of terms, of course. Which is a lot more fun with infinite sums 
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| « Last Edit: Jul 9th, 2009, 6:46am by towr » |
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Wikipedia, Google, Mathworld, Integer sequence DB
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Grimbal
wu::riddles Moderator
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Re: Live action maths debating...
« Reply #2 on: Jul 9th, 2009, 2:23pm » |
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I'm not sure. He sold for $30 a horse that is worth $20 and then bough a horse that is worth $40. He has lost spent* money, but the value of the horse has increased by twice that amount.
I am sure a Goldman-Sachs accountant would see it like that.
* or actually invested
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| « Last Edit: Jul 10th, 2009, 9:44am by Grimbal » |
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Benny
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Re: Live action maths debating...
« Reply #3 on: Jul 9th, 2009, 5:46pm » |
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You beat me to it!
I was going to post gems in financial dealings.
The problem you posted was one of the problems I had in mind.
You could use 2 approaches that would give you two different answers. The first approach gives you $10 but the second one gives you $20.
This problem is one of the tricks used to cook up the books.
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If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
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