Thirty students took a calculus exam. Of the students who passed the exam, 8 students earned an A, 9 earned a B, 6 earned a C, and 3 earned a D. If a single student is randomly chosen, what is the probability that the student did NOT pass the exam? Provide the final answer as a fraction.

Pyotr tchaikovsky sporting goods operates on a 45% overhead based on the selling price, which results in an overhead of $65.34 on the newest version of an air hockey game set. if the air hockey game set costs pyotr tchaikovsky sports $49.32, find the selling price, the markup, and the net profit.