AMC 8 Daily Practice Round 8
Complete problem set with solutions and individual problem pages
Lily's average score for the first several math quizzes this semester is points. If she scores points on the final exam, her average math score for the semester (including the final) will increase to points. How many math quizzes (excluding the final) has she taken so far this semester?
- A.
- B.
- C.
- D.
- E.
The final exam score is points, and the average will become points.
This means the final exam is points higher than the average, and these extra points can be used to raise the earlier average to as well.
The previous average score was , which is points below .
So the extra points from the final exam can be split into three -point gaps, exactly enough to fill the difference.
Therefore, there were earlier scores of , meaning there were math quizzes before the final.
So the answer is .
