Any marks above this is known as a Q+
Any marks below this is known as a Q-.
Getting Q- usually results in an automatic fail on that exam/assignment/quiz/course.
Mathematically, the PDF of the Q-point is Rayleigh distributed (With Marks on the X-axis, from 0% to 100%)
checks Asian girl's marks.
Student B:"Not good man... Not good... Q-point..."
Professor: "See 'ya next year!"