A family has been arguing over the answer to a simple maths question, sparking a heated debate online once their responses and reasonings for their answers were revealed
This maths brainteaser stumped a lot of people (Stock Photo)(Image: Getty Images)
A simple maths question has “torn a family apart” as they argue over the correct answer. The maths question has sparked a debate on social media, as other users weigh in with their calculations and take the argument one step further.
The problem, which has more than 1,000 comments on Reddit, reads: “I bought a cow for $800. I sold it for $1000. I bought it again for $1100. I sold it again for $1300. How much did I earn?” After the question was shared in a group chat, the family members set about answering it, with one admitting: “This had my brain working too hard”, before concluding the answer to be: “$300.”
However, someone else in the chat believes the seller would have earned $500, while another strongly shared how it’s $400.
They said: “My mother-in-law posted this question in our family group chat the other day, and we still can’t convince her that the answer is $400.
“My husband and I have tried with Monopoly money, breaking it down on a calculator, using fake banking apps, and straight up googling the answer – I don’t know how else to explain it at this point unless we’re both missing something.
“My reasoning for it being $400? Splitting it into basic math as follows:
- 800 + 1000 = 200
- 200 – 1100 = 900
- 900 + 1300 = 400
“I think where they’re getting confused is trying to repay $100 somewhere, but no matter how I explain it, it’s like trying to convince someone the sky is actually lime green.”
Commenting on the post, one user said: “Revenue: $2300 Expenses: $1900. Profit = $400. Maybe it’s the order that’s screwing them up.”
Another user added: “So, I can see how my mother-in-law came up with $300.
- First sell is a $200 profit (1000 – 800)
- Buy back at a $100 loss (1000 – 1100)
- Sell it again for another $200 profit (1300 – 1100)
- $400 profit – $100 loss = $300 earned.
“It’s wrong – the correct answer is clearly $400 – but I thought I’d clarify how someone could get to $300.”
A third user said: “This is exactly like those ‘I owe you, you owe him, he owes her’ brainteasers that trick people into double-counting the same 100 bucks.
“Your math is right – it lands on 400. At this point, I’d just say, ‘OK, cool, enjoy your imaginary missing $100’ and tap out.”
One more person added: “I think maybe people get tripped up by selling the cow for $1,000 then buying it again for $1,100, like those two things are somehow connected in their mind.
“But if you change it into two cows – cow A bought for $800 and sold for $1,000, and cow B, a separate cow, bought for $1,100 and sold for $1,300 – they would have no trouble working out the profit is $400 for both transactions.”
0 Comments