in an examination ,the average marks obtained by the students was found to be 60.after omission of computational errors,the average marks of 100 candidates had to be changed from 60 to 30 and the average with respect to all the examinees came down to 45 marks.the total number of candidates who took the exam was how much?

• avg marks obtained is given as 60 i.e for all the children. Let the total children be X.
  now, total marks= 60X
  100 students marks has to be decreased by 30 from 60
  hence, marks need to be deducted from total marks= 60X-3000
  now, average --> 60X-3000/X= 45
  on solving, X=200
• 7 years agoHelpfull: Yes(9) No(0)
• (100*60 + k) / n = 60
  (100*30 + k) / n = 45
  
  solve for n
  we get n = 200
• 7 years agoHelpfull: Yes(3) No(1)
• Let total no of students be x
  so total marks=60x
  now after decreasing marks of 100 students on an average of 30=100*30=3000
  New total marks=45x
  Difference =60x-45x=15x
  and
  15x=3000(because after decreasing 3000 marks , the total marks came from 60x to 45x)
  x=200 Ans
• 1 year agoHelpfull: Yes(1) No(0)
• Let the total examinees = (100+x)
  x*60+100*30 = (x+100)*45
  60x+3000 = 45x+4500
  15x = 1500
  x=100
  hence total examinee = 100+100 = 200
• 1 year agoHelpfull: Yes(0) No(0)