AMC8 1992

AMC8 1992 · Q13

AMC8 1992 · Q13. It mainly tests Averages (mean).

Five test scores have a mean (average score) of 90, a median (middle score) of 91 and a mode (most frequent score) of 94. The sum of the two lowest test scores is

五个考试成绩的平均分（均值）为90，中位数（中间成绩）为91，众数（最频繁成绩）为94。两个最低考试成绩的和是

(A) 170 170

(B) 171 171

(D) 177 177

(E) not determined by the information given 无法由给出的信息确定

Answer

Correct choice: (B)

正确答案：（B）

Solution

Answer (B): If the mean is 90, then the sum of all five scores is 5 × 90 = 450. Since the median of the five scores is 91, at least one score must be 91 and two other scores must be greater than or equal to 91. Since 94 is the mode, there are two scores of 94. The sum of the remaining scores must equal 450 − (94 + 94 + 91) = 171.

答案 (B)：如果平均数为90，则五分总和为5 × 90 = 450。中位数为91，因此至少有一个分数为91，且另外两个分数大于或等于91。94为众数，因此有两个94。剩余分数之和须为450 − (94 + 94 + 91) = 171。

Topics

AR.006 Averages (mean)