We invite you to solve the English version of the RTSdécouverte monthly problem:

**Problem in the dark**

You enter a room. On a table there are some counters, each of which has a red side and a blue side. Twenty of these counters have their blue side facing up while the others have red facing up.

Your task is to separate the counters into two piles, not necessarily of the same size, but so that each pile contains exactly the same number of counters with blue side up. To do this, you can turn over as many counters as you like.

Here’s the catch: the room is in total darkness.

How would you separate the counters into two piles so that each pile contains the same number of counters with blue side up?

Stay tuned for the solution in our next Newsletter…