* Data Collection Challenges: Colleges don't uniformly track this specific information across all applicants and students. Admission standards vary widely, and some students might be admitted despite failing grades, while others might have successfully appealed failing grades or received alternative credit.
* Definition of "Failing": The definition of a "failing grade" can differ between high schools and even within a single school across different subjects and grading scales.
* Privacy Concerns: Data on individual student academic records is considered private and isn't generally made publicly available in aggregate form to answer this kind of query.
While precise figures are unavailable, it's safe to say that a significant number of college students have had at least one failing grade in high school. Many colleges employ a holistic admissions process, considering factors beyond GPA, such as extracurricular activities, standardized test scores, letters of recommendation, and demonstrated potential for improvement. Students with failing grades might be admitted on the condition of academic probation or through programs designed to support students who need extra help.