Result of A Different Clock for Maggie...Challenge #37
Here is the original challenge, and a good reply! Zeno's had over 200 entries!!!
Charles, feeling smug as a result of the last challenge responses (and breathing easier!), posed the following challenge to Maggie, who fancies herself to be a creative problem solver, especially when it involves time and relativity. Each night at Zeno's a bell is sounded by Maggie, signaling closing time in precisely 45 minutes. Charles' challenge to her (and you Zeno's patrons) is this:
Tonight, when Maggie strikes the bell, all of the usual clocks will be removed. The challenge is to determine precisely when 45 minutes has lapsed after the bell sounds. The new 'clock' setup is as follows....There will be two lengths of rope, and each one can burn in exactly one hour. Of course, they are not necessarily of the same length or width as each other, nor are they of uniform width---may be wider in middle than on the ends---thus, burning half of the rope isn't necessarily 1/2 hour. By burning the ropes, one must measure exactly when 45 minutes is up.
Reply to the challenge:
Thanks goes to Troy Williamson, a good patron at Zeno's, and to so many other winners!! Good job!!!!!!
1. Light both ends of rope #1 and one end of rope #2.
2. When the two burning portions of rope #1 meet, 30
minutes will have elapsed. Additionally, one-half of
rope #2 will have been burned, meaning that there is
only thirty minutes of burning time remaining on that
rope. At this time, light the other end of rope #2.
3. When the two burning portions of rope #2 meet, another
fifteen minutes will have elapsed, giving you a forty-
five minute interval (from the time when the first
three fires were lit in step 1 above).
Thanks to all!!!