Came across this maths exercise yesterday and got it wrong until it was explained to me, like to a small child :) Well I was never a maths wiz, but can you do any better? Leave your answer in the comments bellow and to make it more fun, as a prize for 1st correct answer I offer a post in eddy.lt on your chosen subject* ;)
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| Lev Nikolayevich Tolstoy |
This exercise was created by Leo Tolstoy more than 100 years ago for 2nd grade parish school students. According to the statistics, this task is solved correctly from 1st time by only 30% of high school students, 20% of university students and about 10% of bank and finance professionals (though I have no idea where these numbers come from).
Task
A merchant is selling hats, whose unit price is 10 rubles.
A customer comes to his shop and checks out a hat. He says that he would like to buy one hat and gives 25 rubles in one note. Because the merchant does not have change, he sends a boy to his old neighbor to break the note. The boy soon comes back and gives the merchant three ruble notes: 10 + 10 + 5. The merchant then hands to the purchaser a hat with 15 rubles of change, thanks for the purchase and bids farewell.
After a few hours into the shop bursts outraged neighbor, yelling that the 25 rubles are counterfeit, and demands the merchant to return his money, otherwise the neighbor will call the police. The merchant does not want a scandal, and with sore heart gives the man genuine 25 rubles.
Question
What loss was suffered by the merchant?
* with backlinks, of around 250 words in length and as long as the theme is at least slightly connected to startups, entrepreneurship, doing business in general or technology. :)
Good luck,
Eddy
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25 rubles. The customer took a hat (worth 10) and 15 rubles in cash.
ReplyDeleteMore details. Assuming he made zero profit from the hat, before the outraged neighbor came, he would have made 0 rubles. When the neighbor came - he had to give him 25 rubles. So he lost 25 rubles in total.
If he would have made any profit from hat, subtract that from 25, and this would give you the loss.
his loss is 30 rubles and a hat (total value 40): 25 gave back to the neighbour, 15 rubles change for the customer, and he kept 10 rubles for himself
ReplyDeleteTo clear things up, let's tell the story a bit differently. We have three actors in the system who can possess value: the merchant, the customer, and the neighbor. Let's draw the timeline of events.
ReplyDeleteIn the beginnging, the merchant has +35 value (the hat worth +10 and, say, +25 note in the counter - so he can later give back something to the neighbor). The customer has 0 value (fake note). And the neighbor has +25 value (three notes, +10, +10 and +5). This is +60 value in total, in the entire system.
In the end, the neighbor still has +25 (he made the merchant return the money) - so he neither gained nor lost anything. The customer has +25 value (a hat worth +10 and cash worth +15). Finally, the merchant can only have +10 in value, so that the system contains the same amount of value, i.e. 35 + 0 + 25 = 60 (the initial situation) = 25 + 25 + 10 (the final situation).
This means that the merchant's possessed value, from the initial state to the final state, changed exactly by 25 rubles; difference is 35 - 10 = 25.
Once again, the neighbor gained nothing. The customer gained +25. And the merchant lost exactly that 25. The total value in the system must not change.
Eddy, tai koks teisingas atsakymas?
ReplyDeleteMindaugas, the correct answer is 25, so Mr. Naktinis is right :) Naktinis - on what topic you would like me to write a blog post?
ReplyDeleteThe merchant lost only a hat (10 rubles) and 15 real rubles that he gave to the conman. Because from all 25 real rubles he kept 10 rubles note, which he later on gave back to his neighbor. Naktinis provided better explanation above.
Sorry for waiting to announce the answer, I did not forget about it, was just waiting for more possible participants :)
Cool :) As you might already know, I am a co-founder of BusyFlow, so a post about web services that build on top of other services, would be interesting. The most interesting thing would be to know how you see BusyFlow in this integrating-apps context. I can give you early access to play around.
ReplyDeleteExamples of what I mean: ifttt.com, hojoki.com, 300.mg, hootsuite.com, streamerapp.com, zapier.com, greplin.com, cloudhq.net, and, of course, busyflow.com.
There are some interesting aspects to these apps: e.g. as a user you give up your access to many services, as a developer you depend on the availability of these services. Also, only recently APIs became advanced and widespread enough to enable such integrating apps.
Great, very interesting subject, will be done :)
ReplyDelete