AMC10 2015 A
AMC10 2015 A · Q5
AMC10 2015 A · Q5. It mainly tests Linear equations, Averages (mean).
Mr. Patrick teaches math to 15 students. When he graded all except Payton's, average was 80. After grading Payton's, average 81. Payton's score?
Patrick 先生教 15 名学生数学。当他批完除 Payton 以外的所有试卷时，平均分是 80。批完 Payton 的后，平均分变为 81。Payton 的分数是多少？
(A)
81
81
(B)
85
85
(C)
91
91
(D)
94
94
(E)
95
95
Answer
Correct choice: (E)
正确答案：（E）
Solution
Answer (E): The sum of the 14 test scores was $14\cdot 80=1120$. The sum of all 15 test scores was $15\cdot 81=1215$. Therefore Payton’s score was $1215-1120=95$.
答案（E）：14次测验成绩之和为 $14\cdot 80=1120$。15次测验成绩总和为 $15\cdot 81=1215$。因此，Payton 的成绩为 $1215-1120=95$。
Topics
Related Questions
Practice full AMC exams on amcdrill.
Try full-length practice and diagnostics at www.amcdrill.com.