The average marks of 100 students were found to be 40. Later

Home » Aptitude » Average » Question

The average marks of 100 students were found to be 40. Later on it was discovered that a score of 53 was misread as 83. Find the correct average corresponding to the correct score

1. 38.7
2. 39
3. 39.7
4. 41

Correct Option: C

On the basis of given details in question ,
Total of correct marks = 100 × 40 – 83 + 53 = 3970
∴ Correct average marks = 3970 ÷ 100 = 39.70
Second method to solve this question with the help of given formula :
Here, n = 100, m = 40 a = 53, b = 83

Correct Average = m +	(a -b)
	n

Correct Average = 40 +		53 - 83
		100

Correct Average = 40 -	30	= 39.70
	100