There is only two more slots for how many candy bars each student has, in the "7" slot there is only one student that has seven candy bars and in the "8" slot there is two students that had eight candy bars.
Ned got an overall grade of 86 percent because if each question is 4 points, then 6×4=24 but if he got a bonus 10 points, then you can do 24-10=14 and then you do 100-14 which equals your answer: 86.
