Another Riddle in Mathematics
The little paradox in probability that I posted earlier in the week seemed to go down quite well so I thought I’d try a different paradox on a different topic from the same book of paradoxes, which is this one:
It’s quite old. I have the first edition, published in 1945, but many of the “riddles” are still interesting.
Here is one which you might describe as being about “knot theory”…
It’s probably best not to ask why, but the two gentlemen in the picture, A and B, are tied together in the following way: one end of a piece of rope is tied about A’s right wrist, the other about his left wrist. A second rope is passed around the first and its ends are tied to B’s wrists.
Can A and B free each other without cutting either rope, performing amputations, or untying the knots at either person’s wrists?
If so, how?
In the Dark 
December 3, 2022 at 7:47 pm
Man A gets on his knees, man B steps inside the rope of A with his right arm and lowers himself, so he gets under the rope of A, then he is free.
December 3, 2022 at 9:00 pm
If one wrist loop is loose enough, the other man can slip his rope under the loose loop and around the hand…
December 4, 2022 at 1:02 pm
Topological equivalent to two chain ring, it is impossible to untagle