The grade point average of the entire class is 84. If the average of one fourth of the class is 96, what is the average of the rest of the class?
Choose the correct choice from the following options
A) 76 B) 77 C) 78 D) 79 E) 80

Rationale: "let x be the number of students in the class . let p be the average of the rest of the class . 84 x = ( 1 / 4 ) 96 x + ( 3 / 4 ) ( p ) x 336 = 96 + 3 p 3 p = 240 p = 80 . the answer is e ."
Answer: E