You need 50%.
Good answers count, bad answers count negative twice (!), missing answers don't count (so don't answer if you don't know).
Default Solaris Unix config is used. The default shell is ksh. If doubts about the correctness of a question, contact the author (86613). Questions are taken randomly out of a list of 342.
You get 1 minute per question. When time is up, a refresh is done.