Two Ropes
Two fifty foot ropes are suspended from a forty foot ceiling, twenty feet
apart. Armed with only a strong knife (and some strong biceps), how much of
the rope can you steal? Assume you can safely fall a distance of ten feet,
and you can only reach a height of seven feet when standing.
How does the answer change if the ropes are only thirty-five feet long?
Source: Internet newsgroup rec.puzzles,
used as Ken's Puzzle of the Day 7/7/94.
Solutions were received from a few people and all had the same basic
answer:
- Tie the two ends together. For the shorter ropes, you'll have to first
swing one as a pendulum (perhaps using the knife for weight), then go get
the other rope and tie them in the center.
- Climb up the rope on one side. Tie a loop in the top of the rope.
- Cut the rope below the loop and feed it through the loop and pull tight.
- Climb across to the top of the other end of the rope and cut it.
- Swing back to under the loop, then slowly lower yourself to the floor.
- You end up with all of the rope except that used for the loop.
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