The man wishes to remove this string loop from his right hand without cutting the string. His right hand is inside his pocket and he isn't allowed to take out this hand from the pocket. He can only use his left hand.
How can he do this?
I have seen the solution but couldn't understand it.
Originally fom: Dick & Fitzgerald, The Book of 500 Curious Puzzles, 1859.
P.S
I got this question from futilitycloset and I am reproducing the question here, just in case I am misunderstanding it.
Since OP says they have seen the solution (of which they are actually a couple that only differ in minor details), but have trouble understanding it, here's my go at explaining what's going on.
In topological puzzles, it almost always pays to think in the simplest possible terms. The exact shape of anything the rope can go around is pretty much irrelevant, so here's my depiction of the gentleman in the picture
If you can find a solution to this puzzle, you can find a solution to the original puzzle.
The easiest solution is then to
just bring the whole elastic hair band through the metal loop.
This corresponds to
bringing the whole rope loop through the waistcoat, going around any protrusions (like the head and the other arm) that don't actually prevent the rope movement) so that the rope finally falls off around the gentleman's legs
A more impressive looking solution is to
Keep one end of the elastic hair band in place, stretch the other end into the metal loop, around the pointy metal bit, and then back.
Which corresponds to
looping one end of the rope loop around the person but inside the waist coat, so that in the end the whole rope loop finally comes loose near the looped arm, which makes the trick seem just a bit more magical
The only actual difference between (all) the solutions is the hole of the waistcoat through which the rope loop finally escapes.
The answer given in the book, and reproduced at Futility CLoset, sounds a bit complicated but does work.
Note that the man is wearing a shirt (long sleeves) with a waistcoat (no sleeves) over it, and the pocket is in the waistcoat.
- Bring the loop up the arm around the shirt sleeve to the armpit, and pull it all the way through the armhole of the waistcoat, coming out by the neck. At this point the loop still goes under the armpit but mostly sticks out the neck.
- Put the loop over the head, and tuck it under the waistcoat so that it is now like a sash worn over the shirt but under the waistcoat.
- Slide the loop down off the left shoulder and out through the left armhole of the waistcoat. Raise the left arm up and out of the loop.
- Pull the loop back in, under the left armpit and into the left armhole of the waistcoat. The loop is now around the torso, under the waistcoat.
- Let the loop slide down the body, going down under the waistcoat and its pocket but over all the other clothes, down to the feet.
Few people still wear waistcoats, but you could still do the same trick with someone wearing a T-shirt that is not tucked into the pants, and instead of a pocket they just have to hold on to the T-shirt with their right hand. It is a bit harder to execute since the holes of the T-shirt are smaller than in a waistcoat, but it still works.
A simple solution, probably not the intended one but the question doesn't forbid it.
Take off the waistcoat.
Unbutton the waistcoat, take out the left arm, slide the waistcoat down the right arm, over the rope, to the right hand, then remove the rope over the waistcoat.
This even works with a short rope or a necklace.
Likely unintended, but I see this as similar to those viral videos showcasing how seemingly impossible knots in electric cords wind up around pieces of furniture. The equivalent here would be simply push the end of the loop into ones pocket and around ones hand.
