**options**

A) 41.66

B) 52.33

C) 46.66

D) 40.33

**SOLUTION**

TOTAL STUDENTS = 80

- Average marks obtained by 80 students in an examination is 50 = 80X50 = 4000 Is average of both passed and failed students that is 80 students total marks
- failed students are 30 as per question.
- If failed students are 30, then 80-30= 50 students (passed)
- 50 passed students average is 55 which means 50×55 =2750
- total average is 4000 and passed students average is 2750
- remaining students average (failed students ) = 1250
- failed students average is 1250 which as to be divided by 30 students

1250/30 = 41.66

**ANSWER = 41.66**