Most tests are graded by computer. All questions on a test are valued equally; no question counts more than any other. The number of questions you must answer correctly to be considered passing depends on the kind of test you're taking. But on most tests, you must answer 60 to 70% of the questions correctly in order to pass.
The typing skills test given to secretarial job applicants is graded for both speed and accuracy. To pass the skills test, you must type at approximately 40 wpm, after penalties for errors.