Codes and Hidden Meaning - March 2004, Stage 2&3

Problems

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Symmetrical Semaphore

Stage: 2 Challenge Level: Challenge Level:1

Someone at the top of a hill sends a message in semaphore to a friend in the valley. A person in the valley behind also sees the same message. What is it?

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Hidden Meaning

Stage: 2 Challenge Level: Challenge Level:1

What is the missing symbol? Can you decode this in a similar way?

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Ancient Runes

Stage: 2 Challenge Level: Challenge Level:1

The Vikings communicated in writing by making simple scratches on wood or stones called runes. Can you work out how their code works using the table of the alphabet?

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Numbered Cars

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

I was looking at the number plate of a car parked outside. Using my special code S208VBJ adds to 65. Can you crack my code and use it to find out what both of these number plates add up to?

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Semaphore Signals

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Semaphore is a way to signal the alphabet using two flags. You might want to send a message that contains more than just letters. How many other symbols could you send using this code?

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Inspector Morse

Stage: 3 Challenge Level: Challenge Level:1

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?

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Brailler

Stage: 3 Challenge Level: Challenge Level:2 Challenge Level:2

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?

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N Is a Number

Stage: 3 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

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?