# Difference between revisions of "2009 AMC 10A Problems/Problem 7"

## Problem

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?

$\mathrm{(A)}\ \frac{12}{5} \qquad \mathrm{(B)}\ 3 \qquad \mathrm{(C)}\ \frac{10}{3} \qquad \mathrm{(D)}\ 38 \qquad \mathrm{(E)}\ 42$

## Solution

Rewording the question, basically, we are being asked "$2$ is $40%$ (Error compiling LaTeX. ! Missing $inserted.) less than what number?" If $x$ represents the number we are looking for, then$40%$(Error compiling LaTeX. ! Missing$ inserted.) less than the number would be represented by $x-0.4x$ or $0.6x$. Thus $0.6x=2$; solving for $x$, we get $x=\frac{10}{3}$, $\longrightarrow \fbox{C}$