You may like to read the article on Morse code before attempting
this question. Morse's letter analysis was done over 150 years ago,
so might there be a better allocation of symbols today?
The machine I use to produce Braille messages is faulty and one of the pins that makes a raised dot is not working. I typed a short message in Braille. Can you work out what it really says?
N people visit their friends staying N kilometres along the coast.
Some walk along the cliff path at N km an hour, the rest go by car.
How long is the road?
Mr Smith and Mr Jones are two maths teachers. By asking questions, the answers to which may be right or wrong, Mr Jones is able to find the number of the house Mr Smith lives in... Or not!
You have worked out a secret code with a friend. Every letter in the alphabet can be represented by a binary value.
Ask a friend to choose a number between 1 and 63. By identifying which of the six cards contains the number they are thinking of it is easy to tell them what the number is.
Thank you Hannah for this well argued, well presented, solution.
The problem was not as difficult as a first glance suggested.
Go to last month's problems to see more solutions.
An example of a simple Public Key code, called the Knapsack Code is
described in this article, alongside some information on its
origins. A knowledge of modular arithmetic is useful.
Can you spot the similarities between this game and other games you
know? The aim is to choose 3 numbers that total 15.