April 23, 2010
Solving Basic Percent Problems
Proportion Method
%
part
=
100
Finding Part of a Whole
Ex: Find 65% of 245.
whole
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Finding a Percent
Ex: What percent of 60 is 52? Round to the nearest tenth of a percent.
Finding the Whole Amount
Ex: Your class is fund-raising and you have collected $207, which is 46% of your goal.
What is the goal?
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29 is what % of 20?
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Equation Method
You can solve a percent problem by translating the words into an algebraic equation.
When using this method, a given percent must be written as a decimal. If you find a
percent, it will work out as a decimal and you must change it into a percent.
The percent of the whole is the part.
The part is the percent of the whole.
"of" translates into multiplication
"is" translates into the equal sign (=)
Finding the Part
Ex: What is 15% of 40?
x = (.15)(40)
x=6
So, 6 is 15% of 40.
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Finding the Percent
Ex: What percent of 48 is 54?
Finding the Whole
Ex: 380 is 80% of what number?
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Solve using your method of choice:
19 members of the ski club, or 38%, are going on the trip. How
many are not going?