Brain Game. Matches


MatchesI’d like to make your day a bit more entertaining, this is why I’ve decided to publish a riddle today. It’s very simple, but, as you already know, even very simple riddles may need your time. I hope, you will enjoy solving it. So, here it is. There are some matches on the table. They are lying so that they form the following equality: XI+I=X. How do you make it correct without touching any of the matches? You may not light, move, add, remove, break (and so on) the matches. Neither can you use additional objects. So, how do you do this?

Please, if you want to solve the riddle yourself, don’t read the responses to this brain game, because you may find the answer already written there. I will publish the correct answer together with the next brain game. You are always welcome to ask questions about the task in case something is not clear. But sorry, I will not answer leading questions.

And here’s the answer to the previous brain game about the flying hummingbird. It was given by Chris – a very good explanation: if the hummingbird weighs 1 gram, the scales will show one gram. As the bird starts to fly the scales will show slightly more than one gram as energy is used to hop (kinetic energy) into flight giving the bird potential energy. As the bird is flying the scales will read one gram since an equilibrium situation between downward thrust of the air having to match the weight of the bird has been reached. As the bird lands the scales will read slightly more than one gram due to the potential energy being turned into kinetic energy and that kinetic energy being dissipated as landing happens. The bird having landed the scales will revert to one gram.

Scott explained a lot in his comment, but his answer wasn’t actually the solution. Thanks to everybody who participated in the discussion. Now you may start the new one.


  1. This one seems very easy – much easier than the previous one about the bird, but I don’t know the answer yet. Thinking…