I also got the answer as 9.570. I can only say, doing physics need exercise to sharpen you mind. It is important to read more books to have new ideas. University level physics can be very tough for normal secondary school students. However, i also found that today secondary school physics seems become to lack of theory. I can even no need to prepared notes to teach my tuition student. IN physics, the concept is the most important part. with one concept right, you can solve many question.