the average marks obtained by 120 students in an examination is 30 if the average marks of passed student is 40 and that of the field students is 10 what is the 25% of number of students who passed the examination
Answer (1)
16th Dec, 2019
Total marks scored = 120x30 = 3600
Let number of students passing be x. Their average is 40.
Number of students failing is 120-x. Their average is 10.
Now, x(40) + (120-x)(10) = 3600
Solving:
40x + 1200 -10x = 3600
30x +1200 = 3600
30x = 2400
x = 2400/30 = 80
So number of students passing = 80
25% of students passing = 25/100 x 80 = 20
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