The Algebra Teacher\'s Guide to Reteaching Essential Concepts and Skills

Name Date

WORKSHEET 2.17: SOLVING PERCENT PROBLEMS

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Use the proportion, percent=

part

whole

, to solve different kinds of percent problems. Follow

these guidelines:

1. Write the percent as a fraction. If possible, simplify the fraction. If you are trying to find
   the percent, writenover 100.


2. Find the number to the right of the word ‘‘of’’ in the problem. This is the denominator of
   the second fraction of the proportion. It represents the ‘‘whole.’’ If you are trying to find
   this number, writenas the denominator of the second fraction.


3. The numerator of the second fraction is the number in the problem that represents
   the ‘‘part.’’ If you are trying to find this number, writenas the numerator of the second
   fraction.

EXAMPLES

What is 30% of 90? What percent of 80 is 40? 60 is 40% of what number?

30

100

=

n

90

3

10

=

n

90

n= 27

n

100

=

40

80

n

100

=

1

2

n= 50

40

100

=

60

n

2

5

=

60

n

n= 150

DIRECTIONS: Solve each problem.

1. What is 55% of 30? 2. 2.6 is 5% of what number?


2. 60 is 15% of what number? 4. 2.4 is what percent of 5?


3. What percent of 25 is 15? 6. Find 90% of 16.

CHALLENGE:Carla found 66

2

3

% of 300 by setting up the following

multiplication problem:

2

3

×

300

1

=200. Was her answer correct? Explain

your reasoning.

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Copyright

©

2011 by Judith A. Muschla, Gary Robert Muschla, and Erin Muschla. All rights reserved.