This prank is great for students or worker-bees, so whether you're stuck in a classroom or a boring meeting this prank is sure to get some laughs.
This prank involves swapping the insides of a dry erase (whiteboard) marker with a permanent marker. The markers look the same when applied to the board, but won't erase. It's the perfect prank to break up the monotony of learning discretization
or reviewing quarterly statistical analysis based on global distribution deterioration.
You can probably guess how I did this by the pictures and this description, but here's how I did it.