AMC10 2016 B

AMC10 2016 B · Q5

AMC10 2016 B · Q5. It mainly tests Averages (mean).

The mean age of Amanda’s 4 cousins is 8, and their median age is 5. What is the sum of the ages of Amanda’s youngest and oldest cousins?

Amanda 的 4 个表兄弟姐妹的平均年龄是 8，他们的年龄中位数是 5。Amanda 最小和最大的表兄弟姐妹的年龄之和是多少？

(A) 13 13

(B) 16 16

(D) 22 22

(E) 25 25

Answer

Correct choice: (D)

正确答案：（D）

Solution

Answer (D): Because the mean is 8, it follows that the sum of the ages of all Amanda's cousins is $8\cdot4=32$. Because the median age is 5, the sum of the two middle ages is $5\cdot2=10$. Then the sum of the ages of Amanda's youngest and oldest cousins is $32-10=22$.

答案（D）：因为平均数是 8，所以 Amanda 所有表亲的年龄和为 $8\cdot4=32$。因为中位数年龄是 5，所以中间两个年龄的和为 $5\cdot2=10$。因此，Amanda 最小和最大表亲的年龄和为 $32-10=22$。

Topics

AR.006 Averages (mean)