2009 AMC 10A Problems/Problem 7: Difference between revisions
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==Solution== | ==Solution== | ||
<math>\longrightarrow \fbox{C}</math> | Rewording the question, basically we are being asked "2 is 40% less than what number?" | ||
If x represents the number we are looking for, then 40% less than the number would be represented by <math>x-0.4x</math> or <math>0.6x</math>. | |||
Thus <math>0.6x=2</math>; solving for x, we get <math>x=\frac{10}{3}</math>, <math>\longrightarrow \fbox{C}</math> | |||
==See also== | ==See also== | ||
{{AMC10 box|year=2009|ab=A|num-b=6|num-a=8}} | {{AMC10 box|year=2009|ab=A|num-b=6|num-a=8}} | ||
Revision as of 18:03, 1 November 2010
Problem
A carton contains milk that is
% fat, an amount that is
% less fat than the amount contained in a carton of whole milk. What is the percentage of fat in whole milk?
Solution
Rewording the question, basically we are being asked "2 is 40% less than what number?"
If x represents the number we are looking for, then 40% less than the number would be represented by
or
.
Thus
; solving for x, we get
,
See also
| 2009 AMC 10A (Problems • Answer Key • Resources) | ||
| Preceded by Problem 6 |
Followed by Problem 8 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
| All AMC 10 Problems and Solutions | ||