Question

风寒温度衡量人在室外有风时感觉到的寒冷程度。风寒温度可用下面的计算式近似：其中 $W$ 表示风寒温度， $T$ 表示以华氏度 $(^{\circ}F)$ 计的气温， $S$ 表示以英里每小时计的风速。 $W=T-0.7\cdot S$

若气温是 $36^{\circ}F$ ，风速是每小时 $18$ 英里，下列哪一项最接近近似风寒温度？

Wind chill is a measure of how cold people feel when exposed to wind outside. A good estimate for wind chill can be found using this calculation: $W=T-0.7\cdot S$ Where $W$ represents the wind chill, $T$ represents air temperature measured in degrees Fahrenheit $(^{\circ}F),$ and $S$ represents wind speed measured in miles per hour (mph).

Suppose the air temperature is $36^{\circ}F$ and the wind speed is $18$ mph. Which of the following is closest to the approximate wind chill?

$18$

$23$

$28$

$32$

$35$

答案：B

知识点：换元法小数估算

难度评级：450

视频讲解：

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文字解答：

代入公式得最接近的是二十三。 $\begin{align*} 36 - 0.7 \cdot 18 &= 36 - 12.6 \\ &=23.4. \end{align*}$

所以正确答案是 B。

Using the formula, we can calculate the wind chill to be $\begin{align*} 36 - 0.7 \cdot 18 &= 36 - 12.6 \\ &=23.4. \end{align*}$

Thus, B is the correct answer.

2023 AMC 8 第 3 题

答案：B

难度评级：450

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文字解答：

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