Multiple choice

In an exam, 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

  1. 200

  2. 210

  3. 240

  4. 180
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let total students be n. Total marks = 60n. After correction, 100 students' average drops from 60 to 30, causing a loss of 100 × (60-30) = 3000 marks. New total = 60n - 3000, and new average is 45. So (60n - 3000)/n = 45, giving 15n = 3000 and n = 200. Option C (240) would come from incorrect equation setup.

Keep practicing — related questions