Answer:
The other end of the rope was not tied to anything
Explanation:
The dog was tied to a rope of 15 feet long and the bone was 30 feet away from where he was tied. The rope used to tie the dog is 15 ft long . But the other end of the rope wasn't tied to anything, this simply means the dog can easily approach and get the bone 30 ft away from where it was tied.
The other end of the rope was not tied to anything . This implies that the dog can simply reach the bone without breaking a sweat. The 15 feet rope was only tied to the dog , so it does not stop the dog from reaching a bone that is 30 ft away.