Question

The average marks of 40 students in an English exam is 72. Later it is found that three marks 64, 62 and 84 were wrongly entered as 68, 65 and 73. The average after mistakes were rectified is

• A. 70
• B. 72
• C. 71.9
• D. 72.1

Answer 1

Answer:

D. 72.1

Total marks of 40 students in the English exam = 72×40 = 2880 correct total marks of the students = 2880 - (68+65+73) + (64+62+84) = 2884 Total Correct Marks = 2884 Correct average = 2884/40 = 72.1