The average marks obtained by 150 students in a certain examination is 50. If the average marks of the passed students are 54 and that of the students who failed are 30, then what will be the number of the students who failed?

25

Let number of failed students = N

ATQ,

N × 30 + ( 150 - N ) × 54 = 150 × 50

30N + 8100 - 54N = 7500

24N - 600

N = 25

So , Number of failed students = 25