The average marks of a class of 22 students is 40 and that of another class of 28 students is 60. Find the average marks of all the students? Options: A) 51.2 B) 59.5 C) 52.8 D) 52.5 E) 52.1

Rationale: "sum of the marks for the class of 22 students = 22 * 40 = 880 sum of the marks for the class of 28 students = 28 * 60 = 1680 sum of the marks for the class of 50 students = 880 + 1680 = 2560 average marks of all the students = 2560 / 50 = 51.2 answer : a"
Answer: A