Weekly Problem 41 - 2011

This magic square has only been partially completed. Can you still solve it...

Weekly Problem 42 - 2011

Four wiggles equal three woggles. Two woggles equal five waggles. Six waggles equal one wuggle. Using these, can you work out which of four values is the smallest?

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?

Weekly Problem 40 - 2011

You may have seen magic squares before, but can you work out the missing numbers on this magic star?

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?

Weekly Problem 44 - 2011

You have already used Magic Squares, now meet an Anti-Magic Square. Its properties are slightly different, but can you still solve it...

Weekly Problem 33 - 2011

The Queen of Hearts has lost her tarts! She asks each knave if he has eaten them, but how many of them are honest...

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.

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.