# Math problem (fun)

Discussion in 'Math' started by strantor, Nov 8, 2017.

1. ### strantor Thread Starter AAC Fanatic!

Oct 3, 2010
4,763
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I took an embarrassingly long time to figure this one out.

Sep 22, 2013
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\$100.

3. ### strantor Thread Starter AAC Fanatic!

Oct 3, 2010
4,763
2,666
yep. I wasted a lot of time trying to move imaginary quantities of money around, and kept losing track.
Then I thought of it a simpler way:
What did she actually leave with? \$70 in goods and \$30 in cash.
My first instinct was to grossly overcomplicate it and I think that would apply to most people, which is why I find it to be such a good brain twister.

4. ### MrChips Moderator

Oct 2, 2009
14,680
4,351
Depends.
What was the cost price of the \$70 worth of goods?
If the cost price is \$0 then the owner has lost \$30.

xox likes this.
5. ### strantor Thread Starter AAC Fanatic!

Oct 3, 2010
4,763
2,666
Oh yeah, and how much did the \$30 devalue due to inflation while she was inside? And is the point at which she left even really where we should draw the line? He could still be losing money as we speak!

6. ### MrChips Moderator

Oct 2, 2009
14,680
4,351
Suppose the lady bought \$70 worth of "fresh" fruit and vegetables.
But all the produce that she bought was past their best due date. The shop owner was going to throw those out at the end of the day anyway.
Owner is out \$30.

7. ### WBahn Moderator

Mar 31, 2012
20,412
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What would the owner have lost if the woman hadn't stolen the money, but instead just came in with her own money and bought \$70 worth of goods and left with the goods and the \$30 in change?

Nothing -- it was a normal transaction.

That transaction is independent of the prior act of theft.

8. ### MrAl Distinguished Member

Jun 17, 2014
3,906
835
Hi,

The 70 paid for 70 worth of groceries is a valid purchase unrelated to what happened before that. Therefore if we dont count profit then that is an extra zero net loss for the owner. If we count profit then if the profit was 20 dollars then that reduces the total loss by 20 dollars. So she gave him 70 for 70 worth of goods, but he only pays 50 for them so he makes back 20 on that deal. Of course it could be only 10, or maybe 30 or 40, we dont know.

Then for the time duration she is gone the value of money has changed a little. She was gone for 5 minutes so we would have to devalue the money for her but not the goods unless the price of the goods went up. Since he had the goods already presumably, the goods only went up for her. If he just got a new truckload in, maybe it went up for him too though.
So we also have the economy to figure in as well as any change of price for the owner during her absence.

But in the long run he made out pretty good because after he found out what happened he burned down the store and collected the insurance money

9. ### GopherT AAC Fanatic!

Nov 23, 2012
7,499
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If the woman had \$70, It is unlikely she would steel money to buy fruit.

10. ### WBahn Moderator

Mar 31, 2012
20,412
5,824
Irrelevant noise in so many ways. First, it has nothing to do with the problem, and second, there are lots of people who steal who have no need to. They even have a clinical name for them.

11. ### GopherT AAC Fanatic!

Nov 23, 2012
7,499
6,234
Note that that clinical term is usually applied to steeling objects, not money. She didn't steal the fruit. Also, clinically diagnosed people usually steal things they don't need. Stealing food or money usually called shoplifting or robbery and those are not clinical diagnoses.

https://www.psychologytoday.com/conditions/kleptomania

Last edited: Nov 11, 2017
12. ### WBahn Moderator

Mar 31, 2012
20,412
5,824
More irrelevant noise. Unless you are somehow claiming that the amount the shopowner lost is now dependent on whether the woman wanted the money, needed the money, felt compelled to take the money, or just likes stealing money.

13. ### GopherT AAC Fanatic!

Nov 23, 2012
7,499
6,234
Sentence fragment...
I'm not sure where you were going with this one. Should I wait for your follow up tweet?

Note: you are no longer limited to 140 characters.

14. ### WBahn Moderator

Mar 31, 2012
20,412
5,824
Think really hard. I'm betting even you can figure it out. Meanwhile, I'm once again done with your trolling and baiting.