Question

the average marks of 20 students in a test was 85 later it was found that the marks of 2 students were recorded as 60 and 70 but actually there were 65 and 75 respectively find the new average after this correction ​

Answer 1

Step-by-step explanation:

• average marks of 20 students=85
• therefore,total marks of 20 students =20×85=1700
• now correct total marks =1700+(65+75-60-70)=1700+(140-130)=1700+10=1710
• now,new average =1710÷20=85.5