AMC10 2014 A

AMC10 2014 A · Q1

AMC10 2014 A · Q1. It mainly tests Fractions.

What is $10 \cdot \left(\frac{1}{2} + \frac{1}{5} + \frac{1}{10}\right)^{-1}$?

$10 \cdot \left(\frac{1}{2} + \frac{1}{5} + \frac{1}{10}\right)^{-1}$ 等于多少？

(A) 3 3

(B) 8 8

(D) $\frac{170}{3}$ $\frac{170}{3}$

(E) 170 170

Answer

Correct choice: (C)

正确答案：（C）

Solution

Note that $10 \cdot \left(\frac{1}{2} + \frac{1}{5} + \frac{1}{10}\right)^{-1} = 10 \cdot \left(\frac{8}{10}\right)^{-1} = \frac{25}{2}$.

注意到 $10 \cdot \left(\frac{1}{2} + \frac{1}{5} + \frac{1}{10}\right)^{-1} = 10 \cdot \left(\frac{8}{10}\right)^{-1} = \frac{25}{2}$。

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