qav (quiz average) = pick 4 best from q1*1.2, q2*1.2, q3, q4, q5. 
total = 0.4*qav + 0.24*m1 + 0.2*m2 + 0.24*f

passing: total >=53.
semester grade = total + 7.*sin( total/100.*3.14159)