A simple but confusing puzzle involving coffee has gotten a lot of people confused on Twitter.
The logic quiz involves a pot of coffee being poured into a network of pipes which lead to four different mugs labelled 4, 5, 7 and 9.
All you have to do is figure out which mug will get the coffee first.
It look easy enough but it can be easily misunderstood.
Since it was originally posted by Twitter user Purp on Thursday it has gone viral and some people are completely stumped.
The key to solving the puzzle is to study the maze of pipes really closely and then you will find out that there is only one possible destination for the coffee.
Have you figured it out yet?
The answer is mug number 5 as all of the other pipes are sealed off.
More observant Twitter users managed to solve it without any trouble.
HT Daily Mail