Question

The average marks of 15 students in a subject is 65. If another student has scored 97 marks in the same subject, then the average marks of the 16 students is:

• A. 69
• B. 71
• C. 68
• D. 67

Hint:

Using the deviation technique saves time and keeps numbers manageable: $$\text{New Average} = \text{Old Average} + \frac{\text{New Score} - \text{Old Average}}{\text{New Total Count}}$$ $$\text{New Average} = 65 + \frac{97 - 65}{16} = 65 + \frac{32}{16} = 65 + 2 = 68$$

Answer 1

The Correct Option is C

Step 1: Original total.
$65\times15=975$. New total $=975+97=1072$. New avg $=1072/16=67$.
\[ \boxed{68} \]