Question

the average marks obtained by 120 students in an examination is 30. if the average marks of passed students is 40 and that of the failed students is 10, what is the 25% of the number of students who passed the examination

Answer 1

Total marks of students is = 120*30=3600 ; And the number of students who passed examination average is =40 ; 40*80=3200; and average marks of failed students is 10 i.e, 10*40=400 total number of students are split in 4:1 ratio thus 25% of 80 is 20.