Computerized adaptive testing (CAT) is used in DataCamp's skill tests, which means that each question you are asked is dependent on your previous responses. (For example, if you get a lot of questions right, you'll be given more difficult questions.)
As a result, answering wrongly to a few advanced questions can still result in a high score, whereas successfully answering more introductory questions will almost certainly result in a lower score than the total number of correctly answered questions.
