Hint to riddle #17: One Minute Inhomogeneous Fuse
17. You have a string-like fuse that burns in exactly one minute. The fuse is inhomogeneous, and it may burn slowly at first, then quickly, then slowly, and so on. You have a match, and no watch. How do you measure exactly 30 seconds?
Difficult to give a clue to this.
We can't cut the fuse in half. There is no reason to think that the halfway point in time will be the halfway point along the fuse. If we just wanted to find the half minute point and we had a stop watch we could light the fuse and observe the half minute point. And of course it wouldn't matter which end we lit, the halfway time point would be the same.
That's all I'm saying on this.
Where next?
Questions Answer
© Nigel Coldwell 2004 - – The questions on this site may be reproduced without further permission, I do not claim copyright over them. The answers are mine and may not be reproduced without my expressed prior consent. Please inquire using the link at the top of the page. Secure version of this page.
PayPal
I always think it's arrogant to add a donate button, but it has been requested. If I help you get a job though, you could buy me a pint! - nigel
