To think that this sum is super simple

[PeerieBreeks]

and can't understand how so many people on Facebook have it so completely wrong (and can justify it to themselves).

Without adding your reasoning, tell me what you think the answer is.

There is still the problem of the $10 loss.

he has not made a $10 loss.

He made 2 separate transactions - both of which were profitable. The fact that someone ELSE made a $10 profit meantime does not affect his balance sheet.

10 dollars

I don’t understand how people are getting 20

First transaction: 10 up
Second transaction: 10 down (now no profit)
Third transaction: 10 up

Overall 10 up

bakingaddict (and ThreeHours) - there is no loss; you can't use the same transaction twice to calculate a profit or loss. He bought for $60 and sold for $70 - profit $10. Those transactions have therefore been accounted for, and you can only look at new transactions, ie bought for $80 and sold for $90, for another $10 profit.

There is no $10 loss. A loss happens when you sell something for less than you bought it for. That didn't happen.

There is a point where he spends 10 more than he had just received, but it's not a loss.

Surely we need to know how much he started with to know what he made? No! Even if he had no money and had borrowed $80 on the Friday morning and paid it back he still would have had $20 profit on Monday morning.

Had 80 in hand , spent 60, his return was 70, profit 10, overall holding now 90.

Spent 80, return was 90, overall holding 100, pay off debt of 80, left with $20 clear profit (assuming no interest on the original loan)

I thought it was $20.

He had the POSSIBILITY of a $30 profit.

He sold and re-bought, so MISSED out on that, but still made $20 overall.

He never lost $10

Surely we need to know how much he started with to know what he made.

No it’s the same whatever he started with. He is still $20 up!

AIBU not give a flying fig about this and all similar twaddle on facebook etc?

Will it satisfy OP and all other smug folk if I just admit I am thick?

I've looked at it again and still get the same answer!

He makes $10 profit when he sells for $70, but this is cancelled out when he buys for $80 because it's costing him another $10.

So when he sells the last time for $90 he is really only $10 better off.
To me, this answers the question of how much he made "in the end".

I agree that it is an issue of comprehension and interpretation, as these problems are designed to be so that everyone disagrees and argues about the answer

No fatbottomed there are four transactions.

After first transaction $60 down and a horse up
Second transaction now $10 up and no horse
After third transaction $70 down and a horse up
After fourth transaction $20 up and no horse.

Profit and loss accounting pairs up the transactions: first two transactions $10 profit, last two transactions $10 profit. You can't also pair up the second and third transactions.

$10

sorry, $10 profit

AIBU not give a flying fig about this and all similar twaddle on facebook etc?

No, but once you've joined in you're committed

frankchickens - perfectly reasonable not to care about this problem, but you better hope the people who run your bank (or any other business you use for that matter) care because keeping track of balances and profit and loss is vital there.

Yeah, I think I have added a step in the mid point - he has $70 and needs $80 [therefore must have borrowed $10 which needs repayment before net profit can be calculated ] but that's not stated.

He spent $60 in the first place, then he got it back and profit of $10. Then he spent $80 so minus his profit he's out of pocket by $70. Then he gets $90 back so he's profited $20.

This thread is really really really annoying me!!!!!! I don't know why! But it's like running fingernails down a blackboard! Need to get a grip!!! And stop reading it!!!!!!

Aaaagggghhh! It's $20, he needs a different past time than selling and buying horses, and needs business advice cos horses are worth far more than he's buying and selling them for

It's pissing me off that I've wasted part of my Sunday morning on it too IShouldGoToBed

I made it 20 profit

but you better hope the people who run your bank (or any other business you use for that matter) care

Hopefully they are doing something more productive than pillocking about on facebook or arguing with strangers about who is the cleverest.

Hopefully they are doing something more productive than pillocking about on facebook or arguing with strangers about who is the cleverest.

Well, I work in a financial institution, but it's a Sunday morning and I can enjoy myself arguing with strangers over this if I wish.

YABU for 'super' simple wording.

[boak]

It'll be the "3 Diners Riddle" next.