2012 AMC 10B 第 7 题

Question

Sammy 做科学项目时观察一只花栗鼠和一只松鼠把橡子藏进洞里。花栗鼠在它挖的每个洞里藏

3

颗橡子，松鼠在它挖的每个洞里藏

4

颗橡子。它们藏的橡子总数相同，但松鼠少用了

4

个洞。花栗鼠藏了多少颗橡子？

For a science project, Sammy observed a chipmunk and a squirrel stashing acorns in holes. The chipmunk hid

3

acorns in each of the holes it dug. The squirrel hid

4

acorns in each of the holes it dug. They each hid the same number of acorns, although the squirrel needed

4

fewer holes. How many acorns did the chipmunk hide?

30

36

42

48

54

设花栗鼠挖了

h

个洞。

Let the chipmunk dig

h

holes

比较

3h

和

4(h-4)

。

Compare

3h

acorns with

4(h-4)

acorns

设两者各藏了

x

颗橡子。花栗鼠用了

\dfrac x3

个洞，松鼠用了

\dfrac x4

个洞。

两者所用洞数之差为四，所以

\dfrac x3 - \dfrac x4 = \dfrac{x}{12}= 4

解得

x=48

。

所以正确答案是 D。

Let the number of acorns they each hid be

x.

Then, the number of holes from the chipmunk is

\dfrac x3

and the number of holes from the squirrel is

\dfrac x4 .

This means

\dfrac x3 - \dfrac x4 = \dfrac{x}{12}= 4

Therefore,

x=48.

Thus, the correct answer is D .

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