# Knot-Tying (With a Twist)

This puzzle is based on one from a Boy Scout event a few years ago. You need basic knowledge of knot tying and a little outside-the-box thinking.

You are given command over three people, and you have to instruct them to tie a clove hitch around a large tree with a 50’ rope. The catch: the tree stands in the middle of a 10’ radius circle that is off-limits to everyone. What do you do?

I managed to solve this fairly quickly (for being 14-15 years old, at least), so I’m curious as to how many of you can solve it.

• Does "the tree is surrounded on all sides by a 10' circle that is off-limits to everyone" mean "there is a circle with radius 10' bigger than the tree that no body can entet"? – Hugh Feb 10 at 0:29
• Ha nice pun (+1) – Yout Ried Feb 10 at 1:03
• Upvote for pun ;) – Riddler Feb 10 at 22:22

Tell one to hold one end and another to hold the other. Have they create a huge pseudo-knot around the tree where one end of the rope (end $$A$$) is above the other, but there's no tie. Make adjustments so the part from the tree to end $$A$$ is as short as possible. Have the third one hold the other part (end/part $$B$$) at the end of the circle. Tell the second one to hold that part from the very end of the rope, walk around the circle to the other end, pass it above end $$A$$ and below where the third one is holding the rope. Pull it tight and you're done.

50' should be enough.

1. Person A holds one end somewhere on the radius. Person B walks around the circle feeding the rope out until they are back with A (20' used plus a bit for the tree and the rope is looped around the tree).

2. Cross the rope, and person A holds the cross while B walks around the tree again (40' used plus a bit for the tree).

3. B feeds the end under the cross that A is holding (the tree side) and takes hold of it on the other end of A

4. B walks another 90° around in the same direction, while A walks the opposite direction 90° holding only the end that she was originally holding (so allowing the cross to tighten).

5. They pull their ends and voila.

Here's a video.

Basically imagine that instead of the pole you have the tree and person A around which person B is tying the knot.

You could

Pull the rope taut against the tree by standing on opposite sides of the restricted zone and walking together. Now tie the knot outside the circle, and walk apart so that the knot gets pulled along the rope until it hits the tree. This is possible if the knot that you mention can be adjusted by sliding it across the rope.

• The question clearly states that you need to tie a clove hitch, so putting a "depends on the knot" in the answer isn't very well justified. – Bass Feb 10 at 9:06