Hi,
I think you should not have any problem if you understand the mistakes you've made.
I think I'm having about the same score as you when I did my SCJP.
But you should put in more effort in memorising the
Java IO,
Applet tag and inner class.
Then, you should be in the reigon of 80's.
Of course, if you're aiming for higher mark, then do study more.
Cheers.
Han Ming