The average of marks obtained by 120candidates was 35. If the avg of marks of passed candidates was 39 and that of failed candidates was 39 and that of failed candidates was 15, the no.of candidates who passed the examination is? Choose the correct choice
A) 50 B) 80 C) 100 D) 110 E) 130
Let the number of candidate who passed = y   Then, 39y + 15(120 - y) =120 x 35   ⇒ 24y= 4200 -1800= 
<gadget id="calculator">4200 -1800</gadget>
<output>2_400</output>
2400 / 24= 
<gadget id="calculator">2400 / 24</gadget>
<output>100</output>
100   100
<result>C</result>
The average of marks obtained by 120candidates was 35. If the avg of marks of passed candidates was 39 and that of failed candidates was 39 and that of failed candidates was 15, the no.of candidates who passed the examination is?