AMC12 2008 A

AMC12 2008 A · Q2

AMC12 2008 A · Q2. It mainly tests Fractions.

What is the reciprocal of $\frac{1}{2}+\frac{2}{3}$?

$\frac{1}{2}+\frac{2}{3}$ 的倒数是多少？

(A) $\frac{6}{7}$ $\frac{6}{7}$

(B) $\frac{7}{6}$ $\frac{7}{6}$

(D) 3 3

(E) $\frac{7}{2}$ $\frac{7}{2}$

Answer

Correct choice: (A)

正确答案：（A）

Solution

Here's a cheapshot: Obviously, $\frac{1}{2}+\frac{2}{3}$ is greater than $1$. Therefore, its reciprocal is less than $1$, and the answer must be $\boxed{\frac{6}{7}}$.

这里有个取巧的方法：显然，$\frac{1}{2}+\frac{2}{3}$ 大于 $1$。因此，它的倒数小于 $1$，答案必为 $\boxed{\frac{6}{7}}$。

Topics

AR.001 Fractions