A deceptively simple children's brainteaser is sweeping the internet as adults struggle to work out the correct answer.
The perplexing puzzle, based around a basic mathematical equation using a range of fruits, asks you to decipher which number each fruit symbolises, similar to algebra, then work out the total.
But the apples, bananas and coconuts appear to be leaving adults completely flummoxed.
It is not clear where the puzzle originated from, but it has been circulating since December and has now resurfaced as Facebook users are still no closer to agreeing on an answer.
The first sum shows that three apples added together amounts to 30, suggesting that one apple is equal to the number 10.
On the second line, it states that one apple (10) plus two bunches of bananas equals 18, which seems to imply that each bunch of bananas is equal to 4.
The next line states that a bunch of bananas (equivalent to 4) minus a coconut equals 2- suggesting that a coconut is equivalent to the number 2.
On the final line, it asks you to guess the total of half a coconut (1), an apple (10) and a bunch of bananas (4).
A quick glance at the puzzle might suggest the answer is 15, however people trying their hand online were coming up with a plethora of different answers.
After one site shared the image on Facebook, almost 400 people tried their hand at solving the riddle.
One Facebook user stated that the correct answer should be 14, seeing as the bunch of bananas on the final line in fact symbolised 3, rather than 4.
Indeed, on closer inspection there are just 3 bananas in the final bunch, and 4 in the rest.
Paul Blanch wrote: "16 - easy! 3 apples = 30; therefore apples are worth 10 Apple - 2 bananas = 18; the apple is worth 10, so the bananas are worth 4. Banana - coconut = 2; the banana is worth 4, so the coconut is worth 2. The last line? Coconut (2) +apple (10) +banana (4) =16."
Jessica Harris agreed that both banana bunches were equal, insisting that there was a small, barely-distinguishable fruit in the last bunch. She said: "Ok. There are 4 bananas in each bunch. Even in the last one, just the 4th banana is much smaller. But regardless, it's 4 points per bunch, not counting each banana separately."
Another user who came to the same conclusion wrote: "It's very simple, and the answer is 16. Each apple stands for 10, while each banana stands for 4 and each coconut stands for 2. You now have the answer."
Obaidullah Khan Barcha said: "On second and third line there are 4 bananas in a bunch but in the last line there are only 3 bananas in a bunch, that's why the answer is 15."
Ethan Pearson agreedm saying: "There is only 3 bananas in the last equation so it equals=15Apple=10, Apple+Apple+Apple=30Banana=4, Apple+Banana+ Banana=18.
"Coconut=2, Banana-Coconut=2Banana=3Coconut+Apple+3 Bananas=15. Answer is = 15."
Perplexingly, one man came to the conclusion that the answer was 20. He commented: "1 apple equals 10, coconut equals 6 and banana bunch equals 4 so your answer is 20."
Frustratingly there is no definitive answer to the riddle, leaving guessers with no choice but to continue scratching their heads.
Dr Kevin Bowman, course leader for Mathematics at the University of Central Lancashire said: 'You can interpret it in many ways; one way is no more correct than another.
"There's no ambiguity in the first equation; 3 apples is 30, so one apple is worth 10.
"But because all the bananas aren't the same, you could say that they all represent different amounts.
"You might even say that the two coconut pieces in the third equation are different sizes, and therefore add up to three quarters or even seven eighths when put together.
"In that sense, there are an infinite amount of possible answers."
This isn't the first mind-bending puzzle to sweep the internet in recent months. Earlier this year, National Geographic's puzzle asking you to identify which direction a bus is travelling in left thousands of adults scratching their heads.
Their version of the popular puzzle showed a yellow bus with identical windows at either end - giving no clue as to which is the front or back of the bus. The correct answer is that - if you're in the UK - the bus is travelling to the right. And the key to solving the puzzle is the fact that you can't see the passenger doors.
In December, an illustration featuring a hidden panda left thousands of people flummoxed as it swept social media.
Hungarian artist Gergely Dudás posted the Christmas puzzle on his Facebook page on 16 December, showing hundreds of hand-drawn snowmen with the single black and white bear hidden between them. It was shared online more than 19,000 times.
- Daily Mail