Strings - Logic/Math Puzzle

Tuesday, May 5, 2009

You have two strings that when you light one end of either string it takes exactly one hour to burn.

The rate at which the strings will burn is completely random and each string is different.

How do you measure 45 minutes?



Solution (Highlight): Light both ends of one string and one end of the other string. After the first string has burnt out 30 minutes will have passed and the first string will be 30 minutes through it's burn time as well(Not necessarily half way through though). Immediately light the other end of the second string. It will take 15 minutes for that string to burn out, resulting in 45 minutes elapsed time.

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