1994 AMC 12 第 5 题

Question

帕特原本想把一个数乘以

6

，却误将它除以

6

。接着，帕特原本想加上

14

，却误减去

14

。这些错误运算的结果为

16

。若使用正确的运算，所得结果将

Pat intended to multiply a number by

6

but instead divided by

6.

Pat then meant to add

14

but instead subtracted

14.

After these mistakes, the result was

16.

If the correct operations had been used, the value produced would have been

小于

400

less than

400

在

400

与

600

之间

between

400

and

600

在

600

与

800

之间

between

600

and

800

在

800

与

1000

之间

between

800

and

1000

大于

1000

greater than

1000

答案：E

知识点：reverse operations linear equations

难度评级：890

小提示：

逆向撤销错误的减法和除法，求出起始数

Undo the mistaken subtraction and division to recover the starting number

大提示：

对这个起始数计算

6x+14

Apply

6x+14

to that starting number

解答：

若起始数为

x

，错误的计算给出

\frac{x}{6}-14=16\text{，}

所以

x=180

。正确的计算应得到

6(180)+14=1094

，它大于

1000

。因此正确答案是 E。

If the starting number is

x,

the mistaken calculation gives

\frac{x}{6}-14=16,

so

x=180.

The intended calculation would produce

6(180)+14=1094,

which is greater than

1000.

Thus the correct answer is E.

1994 AMC 12 第 5 题

答案：E

难度评级：890

小提示：

大提示：

解答：

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