In an examination, there are three papers each of 100 marks. A candidate obtained 53 marks in the first and 75 marks in the second paper. How many marks must the candidate obtain in the third paper to get an overall of 70 per cent marks?
82
Total marks = 300. 70% of 300 = 210.
Already obtained = 53 + 75 = 128.
Required in third = 210 - 128 = 82.