A rather tricky brainteaser that was posted by distance learning provider Oxbridge during lockdown has proved rather frustrating for even the smartest of people!
The illusion features background of books stacked among one another in varying colours of blue, green, orange and red.
People are then asked to find the yellow pencil hidden between the books - can you spot it?
Apparently the time to beat is less than 20 seconds... good luck!
Oh, what was that?
You give up and want to know the answer? Or you think you have found it and want some clarification?
That's okay, just scroll below and the answer will be revealed...
Here it comes...