AMC10 2009 A

AMC10 2009 A · Q7

AMC10 2009 A · Q7. It mainly tests Percent.

A carton contains milk that is 2% fat, an amount that is 40% less fat than the amount contained in a carton of whole milk. What is the percentage of fat in whole milk?

一盒牛奶脂肪含量为2%，这是全脂牛奶同体积脂肪含量的40%少。全脂牛奶的脂肪百分比是多少？

(A) $\frac{12}{5}$ $\frac{12}{5}$

(B) 3 3

(D) 38 38

(E) 42 42

Answer

Correct choice: (C)

正确答案：（C）

Solution

Answer (C): Suppose whole milk is $x\%$ fat. Then $60\%$ of $x$ is equal to 2. Thus $ x=\frac{2}{0.6}=\frac{20}{6}=\frac{10}{3}. $

答案（C）：设全脂牛奶的脂肪含量为 $x\%$。那么 $x$ 的 $60\%$ 等于 2。因此 $ x=\frac{2}{0.6}=\frac{20}{6}=\frac{10}{3}. $

Topics

AR.003 Percent