This Simple Math Riddle Blows Peoples' Minds. Can You Solve It?

A math riddle caused quite a stir on the internet as hundreds of people went out of their way to solve it correctly. The final answer unveiled a twist no one saw coming.

A user of the parenting website and forum Mumsnet, PeerieBresks stumped the internet with a tricky riddle. The question, which seems simple at first glance, has thrown off lots of people who ended up stuck midway in an attempt to figure out the right answer.

However, some have painstakingly walked through the daunting mathematical process and arrived at an answer. The only problem was, these answers to the simple math problem presented by netizens differ, with each person believing theirs to be the right one.

HOW MUCH MONEY?

So far, the riddle has racked hundreds of comments, giving room for a heated online debate. The math riddle reads:

"A man buys a horse for $60. He sells the horse for $70. He then buys the horse back for $80. And he sells the horse again for $90. In the end, how much money did the man make or lose? Or did he break even?"

The poster urged participants to send in only their final answers without delving into details of the process involved in arriving at the answer.

STUMPED FOR SOLUTIONS

Users of the parenting forum got to work immediately, throwing in a slew of potential answers. $10, $20, and $30 dominated the comments.

Some explained how they arrived at their answers, using logical math theorems and procedures, all seeming genuine. In the end, it became a matter of deciding if the man made some profit from the horse transaction or ran at a loss.

THE BEST ANSWER

Businessinsider.com took up the riddle and proffered the best possible solution, along with a detailed explanation of how to solve the math problem.

Given the poster's question arose from a long-existing riddle, those familiar with it agree with the platform's suggestion that the right answer was $20.

WHY $20

Like most riddles, PeerieBresk's question deliberately comes with a twist designed to throw people off, deviating them from the right solution.

In this case, by mentioning that the man sold the horse for $70 and bought it back at $80, many would naturally be misled to believe he ran at a loss of $10.

However, the trick around it is to picture each trade as a separate transaction. Hence, paying $60 for a horse and selling it off at $70 was one transaction.

Then buying a horse at $80 and selling it at $90 represents a second transaction. Translating the word problem to ideal math equations would look like this:

-$60 + $70 = $10

-$80 + $90 = $10

By implication, the man made $10 from each transaction. Therefore, to answer the question of how much the man gained or lost, one only needs to add up the outstanding balance from each sale. Hence,

$10 + $10 = $20

That gives the correct answer to the viral math riddle as $20.