Not Rachel. ("Rachel received neither an A nor an F.") Not Pat. ("Pat got a lower score than Rachel.") Not Bill. ("Bill scored below Sue.") Nor Andy. ("Andy scored higher than Rachel but not Bill.") ====> The only remained possibility is Sue.
Bill B Andy C Rashel D Pat F
Grades: A, B, C, D, F
Rachel > Pat
Andy > Rachel
Bill > Andy
Sue > Bill
Since no 2 grades repeat, and each grade was assigned, from above, we get: