Question

In a 100-marks test, the average of marks scored by 50 students was found to be 65. Later on, it was discovered that a score of 88 was misread as 68. Find the correct average.

• A. 65.60
• B. 65.50
• C. 65.70
• D. 65.40

Answer 1

Answer:

D. 65.40

Initial total marks (with error):
$50 \times 65 = 3250$

The mistake: 88 was recorded as 68, so 20 marks were missing.

Correct total:
$3250 + 20 = 3270$

Correct average:
$\frac{3270}{50} = 65.4$

Final Answer: 65.4