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problem
In a box
Chris and Jo put two red and four blue ribbons in a box. They each pick a ribbon from the box without looking. Jo wins if the two ribbons are the same colour. Is the game fair?
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problem
Substitution cipher
Find the frequency distribution for ordinary English, and use it to help you crack the code.
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problem
Wipeout
Can you do a little mathematical detective work to figure out which number has been wiped out?
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problem
M, M and M
If you are given the mean, median and mode of five positive whole numbers, can you find the numbers?