Question

When the marks of a student were wrongly entered as 53 instead of 23, the average of the class increased by 0.5. Find the number of students in the class?

Answer 1

Answer:

Number of students was 60

Step-by-step explanation:

Let the total students be x .

Average = total / number of students

First case

Average = total / x ............( 1 )

Second case

53 was written .

Now it was reduced to 23 .

Change = 23 - 53 = - 30

Total = total - 30 .

Average decreases by 0.5

So : average - 0.5 = ( total - 30 ) / x ................( 2 )

Subtract ( 1 ) and ( 2 ) :

0.5 = total / x - ( total - 30 ) / x

= 0.5 x = total - ( total - 30 )

= 0.5 x = 30

= x = 30/0.5

= x = 300/5

= x = 60

Answer 2

60 is the answer hope it is helpful