How stupid is the internet?

[Nearly Sane]

How is this hard?



http://www.bbc.co.uk/bbcthree/article/2dbdaba5-e689-4863-9d82-5aa45ad15068

[Gordon]

It isn't - it is simple arithmetic.

Amazed that anyone would struggle with it.

[jeremyp]

Some people were clearly working on the differences between each pair of transactions i.e.

He pays 60 then gets 70, difference is +10.

Then he pays 80 difference is -10 which cancels out the +10  <<=== This is where it goes wrong

Then he gets 90, difference is +10.

but you can figure out that it is wrong simply by adding up the total amount paid out and the total amount paid in, they are 140 and 160 respectively.

[Harrowby Hall]

In the end, how much money does the man make or lose?

So, does this mean that this relates to a single series of transactions, or are there two separate sets of transactions? My interpretation of "in the end" is that we are dealing with a single series of transactions from a single pot of money. He ends up $10 better off.

[Walter]

It isn't - it is simple arithmetic.

Amazed that anyone would struggle with it.

it appeared on mumsnet forum and caused a fuss . not sure if that is relevant?   

[Gordon]

There are two buying and selling transactions involving the same horse, although the horse aspect is irrelevant: the key point is that each episode of buying and selling (of the same horse) results in a $10 profit - therefore he is $20 better off in the end. 

[Stranger]

In the end, how much money does the man make or lose?

So, does this mean that this relates to a single series of transactions, or are there two separate sets of transactions? My interpretation of "in the end" is that we are dealing with a single series of transactions from a single pot of money. He ends up $10 better off.

No.

He pays out $60 + $80 = $140 and gets back $70 + $90 = $160 and therefore makes $20.

If you consider a 'pot of money', he puts is $60, gets back $70, puts in another $10 for the second purchase, (total $70 in) and gets back $90. $90 - $70 = $20.

[Rhiannon]

Why does this prove the Internet is stupid? I’m confused.

[Harrowby Hall]

He starts with no money.

The horse costs $60. He has a liability of $60.

He sells the horse for $70. He pays off his liability and has a surplus of $10.

He buys the horse now for $80.  He has $70 from the sale but still requires a further $10. This leaves him with a new liability of $10.

He sells the horse for $90. He pays off his liability of $10 and is left with a surplus of $10.

[Udayana]

He starts with no money.

The horse costs $60. He has a liability of $60.

He sells the horse for $70. He pays off his liability and has a surplus of $10.

He buys the horse now for $80.  He has $70 from the sale but still requires a further $10. This leaves him with a new liability of $10.

He sells the horse for $90. He pays off his liability of $10 and is left with a surplus of $10.

Not adding up HH, .. you have paid off $10 too much in the last step.

[Udayana]

Why does this prove the Internet is stupid? I’m confused.

It's like a huge sprawling committee. Impossible to come up with anything that works as everyone keeps throwing in their own misguided opinions or misinformation.
 

[Stranger]

The horse costs $60. He has a liability of $60.

Total: -$60

He sells the horse for $70. He pays off his liability and has a surplus of $10.

Total: +$10

He buys the horse now for $80.  He has $70 from the sale but still requires a further $10. This leaves him with a new liability of $10.

No, as you just said, he already used $60 to pay off his initial liability. He has $10 and he needs another $70.

Total: -$70

He sells the horse for $90. He pays off his liability of $10 and is left with a surplus of $10.

No. He uses $70 to pay his liability and is left with $20.

[Gordon]

He starts with no money.

The horse costs $60. He has a liability of $60.

He sells the horse for $70. He pays off his liability and has a surplus of $10.

He buys the horse now for $80.  He has $70 from the sale but still requires a further $10. This leaves him with a new liability of $10.

He sells the horse for $90. He pays off his liability of $10 and is left with a surplus of $10.

Nope.

1. He buys the horse for $60: so he is - $60.

2. He then sells for $70: so he is now +$10.

3. He then buys back for $80: so his net position is now -$70.

4. Finally, he sells for $90: so he ends up with a profit of $20.

Taken over the transactions he outlays $140 (60 + 80) and gets back $160 (70 + 90).

[Rhiannon]

He starts with no money.

The horse costs $60. He has a liability of $60.

He sells the horse for $70. He pays off his liability and has a surplus of $10.

He buys the horse now for $80.  He has $70 from the sale but still requires a further $10. This leaves him with a new liability of $10.

He sells the horse for $90. He pays off his liability of $10 and is left with a surplus of $10.

Where in the question does it say that he gets into debt to make the second transaction? Or that he had no money to start with?

ETA this is the mistake my 16 yr old made. My 14 year old saw them as two separate transactions and arrived at the 20$ answer.

[Walt Zingmatilder]

You idiots it's an alien plot to put a brain eating meme in your brains!!!

[Rhiannon]

It's like a huge sprawling committee. Impossible to come up with anything that works as everyone keeps throwing in their own misguided opinions or misinformation.

Hello Udayana, good to see you. 

[Stranger]

Where in the question does it say that he gets into debt to make the second transaction? Or that he had no money to start with?

It doesn't actually make any difference - whatever way you look at it, he ends up $20 better off than he started.

[Udayana]

Hello Udayana, good to see you. 

.. just popped in .. been busy studying "group theory" .. which has been rather time consuming...

[SteveH]

$20. I thought "Dim Sum" was a style of Chinese cooking.

[Rhiannon]

It doesn't actually make any difference - whatever way you look at it, he ends up $20 better off than he started.

But it makes a difference to HH.

[Walter]

But it makes a difference to HH.

in todays modern world , the answers to a maths problem is what you want it to be . It's how it makes you feel that's important. 

[Udayana]

in todays modern world , the answers to a maths problem is what you want it to be . It's how it makes you feel that's important. 

lol ...only if Dame Slap has set the questions

[Stranger]

.. been busy studying "group theory" .. which has been rather time consuming...

...but rather beautiful (IMO).

[Harrowby Hall]

But it makes a difference to HH.

I was trying to follow the flow of cash - nothing to do with getting into debt. Think of it as money going between your wallet and that of your husband.

Anyway, I'm sure that the accountancy profession is relieved that it will not receive a takeover bid from me.

[Udayana]

...but rather beautiful (IMO).

Apparently, but tbh. at the moment I can't see the wood for the trees.