The rule-of-24s method of earning is an Exam 5 topic. Generally, Exam 6 expects candidates to be familiar with the material on the preceding exams, including Exam 5. It is not quite reasonable to expect one to remember everything from a prior exam. But in this case, I believe the comment on the error in earning was only one of the acceptable answers.
Comments
The rule-of-24s method of earning is an Exam 5 topic. Generally, Exam 6 expects candidates to be familiar with the material on the preceding exams, including Exam 5. It is not quite reasonable to expect one to remember everything from a prior exam. But in this case, I believe the comment on the error in earning was only one of the acceptable answers.