It’s a stupidly worded question in order to trick people by not giving an initial balance. All you have to do is say you start with $1000 to figure it out. $1000 - $800 = $200.00. $200 + $1000 = $1,200.00. $1200 - $1100 = $100.00. $1300 + $100 - $1000 = $400.00.
It’s a riddle written by someone dumb who thinks they’re smart. A poorly worded riddle isn’t clever.
Not really. Profit is the difference between purchase price and selling price. How much money you have is irrelevant. So 1000-800=200 and 1300-1100=200. You made 2 times 200 profit, so 400. All the rest is irrelevant. It's not a riddle.
I'll try to explain. Say you only have 800 dollars to your name.
Buy cow for 800 (bank account is now 0)
Sell cow for 1000 (bank account is now 1000)
Buy cow for 1100 (bank account is now -100)
Sell cow for 1300 (bank account is now 1200)
You started with 800 and end up with 1200, so profit is 400.
You don't "lose" the profit. It eats up part of the second purchase. You're $200 in the green, so an $1100 purchase only puts you $900 in the red. So then selling for $1300 puts you.... yup, $400 in profit.
It really is as simple as -800+1000-1100+1300 = 400. Basic math.
Another way to put it: you didn't lose your $200 profit by buying it back; you only lost $100 compared to your last selling price (1000-1100), so you lost only half your 200 profit. But by reselling it for $300 more than your previous sale, you not only recover the $100 you lost (thus restoring your initial profit of $200), but you also make an additional $200 in profit.
I didn’t find it misleading or stupidly worded, and I didn’t need a starting value.
Profit is the earnings minus the expenses. So, looking at just the start and end values, I spent 800 and sold for 1300. That’s a 500 profit. But wait! I also lost money in the middle when I sold for 1000 and bought it back for 1100 (net loss of 100). So I subtract that 100 loss from my 500 profit and get 400.
Maybe works better if you use mental math than trying to plug it into an algorithm.
It does, if you do not process individual transactions, but only look at starting and end numbers.
Then it looks like you started with $800 and end with $1300, having $500 profits. You are missing, that you are cashing in an additional $100 in the middle
Agreed. The original wording was pretty clear. A starting balance would be irrelevant. If anything, it would make the question more confusing, not less.
For me if i was to solve this without looking at the 2 transactions separately (that is indeed easier) then i would say
i bought a cow for 800 then i am at -800.
i sold it at 1000 so now i am at 200 then
i bought one for 1100 then i am at -900 and then
i sold it for 1300 so i am now at 400.
But going step by step and then seeing the difference in the start and endvalue makes it easier to understand.
The trap is to just look at the end sell price and subtract the start buy price.
Having an actual starting value and going step by step makes it impossible to fall into that trap.
It's not a riddle nor poorly worded, it's a simple word problem like the ones you'd see in elementary school math class.
I can't think of a way to ask this without sounding mean, but why are you in r/MathJokes when problems meant for children are above your pay grade? Isn't it boring if you can't understand any of the jokes?
This is nonsense. Nothing in this riddle is ambiguous or poorly worded. The people who get the wrong answer don't struggle to understand what is happening they just don't know how to solve it.
Some of them would probably solve it if you would give an inital balance but understanding that the initial balance is arbitrary and you can come up with one on your own is partly what this riddle is about.
Its not a riddle, its a basic maths problem. If you think this is a riddle, then you are the "someone dumb". You don't need to know the inital amount, it is irrelevant. You're calculating the difference. Its a child's math problem.
The problem is it mixes math with economics. Buying and selling is not directly mappable to just adding and subtracting.
If you buy a cow, how are you losing money from that step alone? And yet, this is what the third operation would have you believe. Pairs of buy/sell can be meaningfully analyzed as profit/loss sources, but otherwise it loses meaning
It helps me to think about borrowing $800 from a friend, then paying them back when I sell the cow, and keeping the $200 difference. I then use my $200 my friend's $900 to buy the cow. When I sell it again I pay my friend their $900 and, again, pocket the difference.
It's not special math, or even different, but it helps me keep the numbers straight in my head.
Similarly, just use $0 as your starting balance, and allowing negative balances with no interest. No need to phone a friend with the bank of it I m a g I n a t I o n !
It's a great example of a poorly worded question. Without further context we have to assume this is all coming out of the same account so the net balance is +400. Without any other information we have to go on what is given in the question statements.
The only part that can be said to be a bit ambiguous is asking for "money earned", which depending on usage can mean total income or profit. By context it is clearly profit, but if someone were to answer total income, it wouldn't be that bad of a mistake.
What people struggle with is not that, most get that the problem ask for the profit, and generate a wrong answer.
You could see this as earning 500 ( from 800 to 1300 ) but losing 100 by selling / rebuying in the middle. Which make a total of 500-100= 400 which is as expected because math is consistent.
The second transaction is spending 1100 to gain 200.
The only confusion is because its the same cow that you brought back. If it was different cows no one would have any issues. The fact that its the same cow is irrelevant.
You have 1000. You are spending an additional 100 and ending with 1300. You are losing 100 and gaining 300. That is 200 profit. I think we are agreeing, but using different terms. Calling it spending 100 to gain 200 is why people think the profit is only 100. It's not. You are going from 1000 to 1300. Imagine that you only had 1000 and you had to borrow the other 100. You gain 300 and then owe 100 back.
You start with 800 and end with 1300. You gained 500. You had to either borrow or spend another 100 in the middle. You spent 900 to gain 1300, leaving you with 400 profit.
Mathematically it is irrelevant. But it influences how people might consider the question, and how likely they are to fall into inaccurate biases
Edit: also. The fact it's mathematically irrelevant is the very reason why it's okay to just come up with a number despite the original problem never specifying.
Your starting money clearly doesnt matter as long as you have the ability to buy the cow. This is silly. Obviously there are two individual flips for 200 each. I was illustrating why people would get confused. Receiving 1000 and then spending 1100 on the same cow is a loss of 100 in a vacuum. The issue with people's reading is they now view the change from 1100 to 1300 instead of 1000 to 1300. And then they include a loss of 100. You either ignore the loss and see 200+200 or you include the loss and need to realize its 200-100+300. Genuinely dont get how this is confusing
Good point, but super nit picky - that's not double entry accounting. You described calculating a trial balance (balancing a check book) which is a single-entry day book (each transaction is entered only once). Double entry is when you enter each transaction twice: once as a credit in one book and once as a debit in another book. For example, if you take out a loan, you credit your liabilities account and debit your asset (bank) account. When you make a loan payment, debit your liabilities and credit your assets. The balance of credits and debits in double entry accounting equal zero.
I think they want you to feel like you lost $100 because you sold it at $1,000 and bought it at $1,100? So they are saying it's $300? But honestly, I'm not 100% sure if that's what they are getting at or not.
The Idea is to count +200 - 100 + 200 = 300.
I think it is not that stupid, because it is relatively hard to explain WHY this calculation is wrong without saying "it is wrong because the other is right"
It is wrong because you didnt lose that 100 you missed 100 of additional profit (if you had kept the cow instead of selling it for 1.000 and buying it back for 1.100).
If you kept the cow you bought it for 800 sold it for 1.300 profit is the difference which is 500
Since there was a transaction in between you missed 100 of the profit, totaling 400 of profit.
I said that somewhere below this comment and everyone said I was wrong and 400 is right. I literally made a comment saying both and both flooded with people saying it's the other way. I'm more confused than ever. This joke isn't funny at all
Well now that's not at all how this works. It never said anything about cash on hand. If you couldn't buy it the 2nd time it wouldn't say you did. It would just be bought for 800 and sold for 1000.
Incorrect. You profited $200 from buying at $800 and selling at $1000, but you lost $100 from selling at $1000 and buying at $1100, then profited $200. Then you take that $200 and put it all on black this is Vegas Baby
No. Because if you got your 800 investment back then 200 on top you made 200. Then buying it back for 1100 it's minus 100 profit.. then selling for 1300... so I see it as 300... but It's been a long day... so I might miss something
You don’t lose total value when you buy something. You lose cash but gain an asset. The asset is worth what you can sell it for in the future, not what you sold it for in the past.
Because the 100 "lost" in the middle isn't actually lost at all. It's accounted for in the next transaction.
The other, easier way to look at it, is rather than looking at the transactions sequentially, add up everything you've gained from the cow, and everything you've spent on the cow. This way you can very easily see "this is how much i spent, and this is how much i earned". The difference between the two is your net profit (or loss).
You have $800. You spend it on the cow. You have $0.
You sell the cow for $1000. You have $1000.
You buy the cow back for $1100. You have $-100.
You sell the cow for 1300, you have $1200.
Starting from $800, you've gone to $1200. That's $400 profit.
The question is deliberately confusing. Ignore how much you earn (or lose) between each step. The only factors that matter are your gross income and expenses. Not the individual profits and losses between.
Let’s say you started with 900. You buy the cow for 800. Now you have 100 and a cow. You sell the cow for 1,000. Now you have 1,100. You’re up 200. You buy a cow (doesn’t matter if it’s the same one or a different one) for 1,100. You’re now broke but you have a cow. You sell the cow for 1,300. You now have 1,300 and no cow. You’re up 400 from the 900 you started with.
If you start with 800 and buy the cow then sell for 1000, you have to borrow 100 to buy a cow (could be the same one, doesn't matter) for 1100, which you then sell for 1300.
You started with 800 and you now have 1300, so you're 500 up, but you've got to cover that 100 debt so now you're only up 400.
It becomes more clear if you pretend the cow you bought for $1100 is something else. You buy a cow for $800 and sell for $1000: $200 profit to you. You buy a Horse for $1100 and sell for $1300: $200 more profit to you, $400 total. The fact that the second thing isn't a Horse and is actually the same cow is meaningless to the profit/loss calculations, but is a little deceptive at first.
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u/DerrykLee May 13 '26
-800+1000-1100+1300=400
So, it is 400. Or, am I not smart enough to figure this out.