The shopkeeper picks one out and says, “This one can cut down five trees in two minutes.”
The lumberjack is impressed by this and buys the chainsaw. Two days later, the lumberjack comes back to the shop with the chainsaw and asks for a refund.
“This is a complete rip-off, I only managed to cut down one tree over the space of an hour!”
The shopkeeper takes the chainsaw and turns it on only for the lumberjack to suddenly jump in surprise.
“What’s that noise!”