2016 AMC 10B 第 5 题

Question

Amanda 的

4

个表亲的平均年龄是

8

，年龄中位数是

5

。她最小和最大的两个表亲的年龄之和是多少？

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?

\ 13

\ 16

\ 19

\ 22

\ 25

四个人的年龄总和是

4\cdot8

。

The total age is

4\cdot8

中间两个年龄的和是

10

。

The two middle ages sum to

10

四个年龄的总和是

4\cdot8=32

。由于中位数是

5

，中间两个年龄的平均数是

5

，所以它们的和是

10

。

因此最小年龄与最大年龄的和为

32-10=22

。

所以正确答案是 D。

The total of the four cousin ages is

4\cdot8=32

. Since the median is

5

, the two middle ages have average

5

, so their sum is

10

.

Therefore the youngest and oldest ages sum to

32-10=22

.

Thus, the correct answer is D.

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