The average marks obtained by 240 students in a certain examination is 35. If the average marks of the passed candidates are 39 and that of the failed candidates are 15, then the total number of candidates who passed the examination is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 200.
Let number of passed students = x
Then failed students = 240 − x
Total marks = 240 × 35 = 8400
Marks from passed = 39x
Marks from failed = 15(240 − x)
So,
39x + 15(240 − x) = 8400
⇒ 39x + 3600 − 15x = 8400
⇒ 24x = 4800
⇒ x = 4800 / 24 = 200