Since this looks very much like a homework question, I don't want to give the answer straight out. However, let me see if I can point you in the right direction.
It looks like you pulled the first two answers from the HashMap class' description in the Java API documents (i.e. the JavaDocs). The third answer is not directly verbalized in the text. But if you carefully compare the HasMap & HashTable entires, the answer is there. Also take a look at this JavaWorld article. From that you should be able to determine what another big difference between HashTable and HashMap is.