Question
The average marks of 90 students in a class was calculatd as 144. It was later realised that the marks of one of the students was 148 whereas, his actual marks was 156. What is the actual average marks of the group of 90 students? (Rounded off two digits after decimal)
A
144.09
B
145.87
C
146.77
D
148.75
Answer & Explanation
Option: [A]
The total marks of 90 students = 90 x 144 = 12960
According to the question, the marks of one of the students was 148 whereas, his actual marks was 156
So, the total marks = 12960 - 148 + 156
= 12968
So the average = 12968/90
= 144.09
