For some, math isn’t an easy subject – especially when it involves a tricky riddle that seems to be stumping just about everyone.

Parenting website, Mumsnet, shared a simple math puzzle on Sunday that asked how much profit a man made (or if he broke even) when he sold and then bought his horse.

The puzzle said: ‘A man buys a horse for $60. He sells the horse for $70. He then buys the horse 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?’

Peerie Breeks, who shared the brain teaser wrote on the website: ‘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.’

But the teaser has left Facebook users more confused than ever with answers varying in the price of how much money he made.

One Facebook user said: ‘Actually its even. He sold it for 70 but had to put another 10 in to buy it 80 . Sold it for 90 made 10 but put in 10 to buy it back at 80.’

Wrong: One man shared on Facebook that the he didn’t understand how people were getting $20

Another disagreed and instead of thinking the man broke even, thought he was down $40.

She said: ‘The man is down $40. Did we forget the original $60 he spent?’

For those that are curious, the man made a $20 profit when he bought and then sold the horse but the answer wasn’t so easy to come by for some people.

One man shared on Facebook: ‘I don’t understand how people are coming up with up 20.’

And after trying multiple times to solve the problem, he added: ‘Up 10, even, then up 10 is what I got!?’

But in order to put any all confusion to rest, someone explained the problem in a comment on Facebook.

He said: ‘He buys a horse for $60. Sells for $70. Put that $10 aside. Buys the horse for $80. Sells it for $90. Another $10 profit.’

This isn’t the first time a seemingly easy puzzle has baffled the internet.

A year ago, a woman shared a confusing brain teaser on Twitter when she realized the puzzle was intended for six year old children.

The question read: ‘There were some people on a train. 19 people get off the train at the first stop. 17 people get on the train. Now there are 63 people on the train. How many people were on the train to begin with?’

The correct answer is 65, which you arrive at by subtracting the 17 people who just boarded from the current number of passengers, 63, to get 46. Then you add the 19 passengers who got off to arrive at 65.

However, similar to the previous brain teaser, the internet was still confused over how to arrive at the answer.

**How to solve the brain teaser that’s stumping the internet**

First, subtract $70 from $60 as the man made a $10 profit when he sold the horse for $10 more than he bought it

Next, subtract $80 from $90 because the man made another $10 profit when he sold the horse again

So the problem would look like:

70-60=10 and 90-80=10

And 10 plus 10 equals 20 which how much the man profited from the horse