Thursday evening flying back home. Puzzle time.
Put 10 coins in four rows – top row has four coins, next has three, next has two and bottommost has one (will look a bunch of grapes – see the picture).
Now by moving only THREE coins, you have to get the bunch of grapes to look like upside down. (so, top row has one coin, next has two….)
This is not a trick question. The arrangement is exactly the same – but upside down.