There are 100 students in 3 sections A, B and C of a class. The average marks of all the three sections was 84. The average of B and C was 87.5 and the average marks of students in A section was  Options:
A) 20	B) 37	C) 28	D) 11	E) 12
Explanation:   Numbers of students in section A = x   âˆ´ Numbers of students in section B and C = (100 â€“ x)   âˆ´ x 70 + (100 â€“ x) 87.5 = 84 100   =&gt; 70x + 87.5 100 â€“ 87.5x = 8400   =&gt; 8750 â€“ 17.5x = 8400   =&gt; 17.5x = 8750 â€“ 8400 =&gt; x = 20.   20nswer: 20
<result>A</result>
There are 100 students in 3 sections A, B and C of a class. The average marks of all the three sections was 84. The average of B and C was 87.5 and the average marks of students in A section was