GMAT Practice Question (One of Hundreds)
Louis has written four papers, on which he has received an average of 78%. His lowest-scoring paper is automatically dropped. After dropping, his average for the three remaining papers is 84%. What was the score of his lowest-scoring paper?
Correct Answer: E
Set up equations for the averages before and after dropping.
- Let T be the total score of the four papers
Let d be the score of the dropped paper.
- The average of all four papers:
T / 4 = 78
- Solve for T:
T = (4)(78)
T = 312
- After the lowest paper, d, is dropped, the sum of the three remaining papers is: T - d.
- The average of the remaining three papers:
(T - d) / 3 = 84
Since we know T:
(312 - d) / 3 = 84
- Solve for d:
Multiply by 3: (312 - d)= 3(84)
312 - d = 252
312 - 252 = d
d = 60
- Answer choice E is correct.