The thing is, the illustration shows a ring of 12 links, not the 15 asked for. For a 12-link chain you make 3 cuts in the links of one chain and use them to join the others in a ring. That is how I would expect the problem to be formluated. To get a 15-link chain from the 12 links available you have to cut 3 of them in half (6 cuts) in order to get 15 links.
No, actually you can do better if the links are large enough: cut one link with 4 cuts into 4 pieces and use them to join the remaining four chains.
Oh man, that was a stupid typo. I was very confused, mostly because I myself hadn’t properly read the question. Edited now; yours is a clever solution though.
Similar puzzles to this one sometimes allow `out-of-the-box’ thinking, where you use a single cut (as in: cleaving action) to cut vertically through all links in a single chain, producing 6 half-links at once.
The thing is, the illustration shows a ring of 12 links, not the 15 asked for. For a 12-link chain you make 3 cuts in the links of one chain and use them to join the others in a ring. That is how I would expect the problem to be formluated. To get a 15-link chain from the 12 links available you have to cut 3 of them in half (6 cuts) in order to get 15 links.
No, actually you can do better if the links are large enough: cut one link with 4 cuts into 4 pieces and use them to join the remaining four chains.
Oh man, that was a stupid typo. I was very confused, mostly because I myself hadn’t properly read the question. Edited now; yours is a clever solution though.
Similar puzzles to this one sometimes allow `out-of-the-box’ thinking, where you use a single cut (as in: cleaving action) to cut vertically through all links in a single chain, producing 6 half-links at once.