A coffee riddle has been puzzling internet users after it was posted on Twitter.
Metro.uk reports a photo of the riddle was posted on twitter showing coffee being poured into a series of pipes leading to four cups.
Users were quick to respond to the tweet with their guesses, but many got frustrated trying to find the answer.
Have a go for yourself, the answer may seem obvious but it pays to have a good look at the riddle before you start, and maybe make yourself a cup of coffee as it could take a while.
Newshub.