The grade point average of one third of the classroom is 60; the grade point average of the rest is 66. What is the grade point average of the whole class?
Choose the correct option.
A) 55  B) 56  C) 64  D) 65  E) 66

Rationale: "let n = total students in class total points for 1 / 3 class = 60 n / 3 = 20 n total points for 2 / 3 class = 66 * 2 n / 3 = 44 n total points for whole class = 20 n + 44 n = 64 n 64 n total class points / n total students = 64 grade point average for total class answer : c"
Answer: C