The question is asking us to answer the following question: It is 3:00pm here, and Australia is 13 hours ahead of us. What time is it in Australia?. What we know is that Australia always has 13 hours "earlier" - this is what it means that it's ahead of us. This means that we have to add 13 hours. first, let's add 9 (4 will be left) hours, we will end up at midnight. Then we add further 4 hours, and we end up at 4 AM. So the answer is that it's 4 AM of the following day.
