Question

The average of marks obtained by 120 candidates was 35. If the average of marks of passed candidates was 39 and that of failed candidates was 15, the number of candidates who passed the examination is:

• A. 100
• B. 110
• C. 120
• D. 150
• E. None of these

Answer 1

The correct option is A 100

Let, the number of candidates who passed = x.
Then $39\times x+15\times (120-x)=120\times 35$
$\therefore$ $24x=4200-1800$
or, $x=\frac{2400}{24}$
x= 100.