Q. The average mark of 10 students is 80%. Later it was found that for one student, instead of 60%, the recorded 90%, by mistake. Now the corrected new percentage?

• lets assume the total marks in the exam per student is 100.
  and given that avg mark of 10 student is 80%
  so, total mark=80*10=800 ;
  but instead of 60 mark they take wrong as 90 mark;
  so,800-90 + 60=770
  this is correct mark of 10 student
  and then average of 10 student is =770/10=77
  
  
• 11 years agoHelpfull: Yes(25) No(0)
• Average marks of 10 students is given as 80% => sum of total marks of 10 students is 10 * 80=800.
  
  by mistake they added 90 instead of 60 for 1 student => Extra 30 is added to the total. therefore the new corrected total becomes 800-30=770.
  
  Now calculate the new average as 770/10=77%
  
• 11 years agoHelpfull: Yes(5) No(0)
• For the sake of simplicity, lets assume the total marks in the exam be 100.
  So, total of 10 students = 10 * 80 = 800
  But the previous total is 30 more than actual total,
  So actual total = 770
  So, the new average is 77%
  The answer is 77
  
• 11 years agoHelpfull: Yes(4) No(0)