While Playing With A Metal Washer Shaped Like A Ring
Riddle: While playing with a metal washer shaped like a ring, Dave accidentally pushed it on his finger too far and couldn't get it off. Trying to remove it using soap and water didn't work. The hospital sent him to a service station thinking they could cut the metal. Since the ring was made with specially hardened steel, it couldn't be cut. Just then Bob arrived on the scene and suggested an easy way to remove the washer in just a few minutes. What was his solution?
Answer: Bob suggested that Dave hold his finger in the air while someone wound a piece of string tightly around his finger just above the metal ring. The string forced the swelling down. As they unwounded the string from the end nearest the ring, someone else slid the ring up. They continued winding and unwinding the string until the ring could be easily removed.
Source: https://www.riddles.com/814
