According to information taken from the College Board website on 2018, based on a scoring calculation called "raw score" for the CLEP exams, the test taker's "raw score increases by one point for each question answered correctly, and no points are gained or lost when a question is not answered correctly or is answered incorrectly."
This means no points will be withdrawn if skipping or incorrectly answering a question. Moreover, regardless of how many questions the exam contains, the number of correct answers will be converted to a scaled score from 20 to 80 points, which will be presented on the test taker's score report.