Two hostages are connected by their wrists. They couldn't untie the knot without cutting the rope, but they escaped. How did they do it?
As shown in the picture, hostage A holds his rope with both hands, so that the rope forms a loose ring on the other side of hostage B. Then A puts the rope ring into the lasso and puts it on his partner's wrist. It is easy to find that the loop can only be twisted by one wrist. Then A winds the rope around B's finger. When A winds the rope around B's hand and pulls it out of the lasso, they are free.