According to folklore, the following riddle was invented by Albert Einstein when he was just a boy.
To add to its mystique, various reports suggest that only two per cent of the world's population can solve it and owing to its difficulty (but logical answer), enjoys immense popularity online, where it has resurfaced again this week.
However, we have strong belief that more than two per cent of i100.co.uk readers can solve it so do let us know how you get on the comments...
There is a street with five houses all in a row. Each house has a person with a different name and each house is painted a different colour. Each homeowner drinks a different type of beverage, owns a different type of pet and reads a different type of newspaper.
Here are the clues to help you solve the puzzle (we've jazzed up the names a bit from the original, just to make things interesting):
Jez lives in the red house.
Liz keeps corgis as pets.
Vlad drinks vodka.
The green house is on the immediate left of the white house.
The green house's owner drinks coffee.
The owner who reads the Morning Star keeps a golden eagle.
The owner of the purple house reads the Daily Express.
The owner living in the centre house drinks milk.
Nigel lives in the first house.
The owner who reads the Guardian lives next to the one who keeps a tiger.
The owner who keeps the stallion lives next to the one who reads the Daily Express.
The owner who reads the Times drinks beer.
Donald reads the Daily Mail.
Nigel lives next to the blue house.
The owner who reads the Guardian lives next to the one who drinks green tea.
To solve the riddle, all you need to work out is: Who owns the goldfish?