you do realize a GPA is a grade point AVERAGE, right?
Say you take 18 credits a semester for 6 semesters, get all As and your 3 Cs in 3 credit courses. Your GPA will be:
3.833.
Or... you could get all Fs and 3 Cs and end up with:
.167
Point: It doesn't matter what 3 individual grades you've gotten. It matters your AVERAGE (hence the acronym GPA) of all the courses you've taken. It is impossible to judge someones GPA (and hence their prospects at medical school) from any 3 grades/courses.