Page 477 - Basic College Mathematics with Early Integers

454 C HAPTE R 6 I PERCENT

PRACTICE 10 Example 10 Solving Percent Equation for the Base
1
27 is 4 % of what number? 1
2 13 is 6 % of what number?
2 5
T T T T T
1
Solution: 13 = 6 % # n Translate to an equation.
2
1
13 = 0.065 # n 6 % = 6.5% = 0.065.
2
13
= n Divide 13 by 0.065, the number multiplied by n.
0.065
200 = n
1
Thus, 13 is 6 % of 200.
2
Check to see if this result is reasonable.

Work Practice 10

PRACTICE 11 Example 11 Solving Percent Equation for the Percent
What percent of 80 is 8?
What percent of 12 is 9?
5
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Solution: n # 12 = 9 Translate to an equation.
9
n = Divide 9 by 12, the number multiplied by n.
12
n = 0.75

Next, since we are looking for percent, we write 0.75 as a percent.
n = 75%
So, 75% of 12 is 9.
#
To check, see that 75% 12 = 9 .
Work Practice 11

If your unknown in the percent equation is the percent, don’t forget to convert
your answer to a percent.

PRACTICE 12 Example 12 Solving Percent Equation for the Percent
35 is what percent of 25?
78 is what percent of 65?
5
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Solution: 78 = n # 65 Translate to an equation.
78
= n Divide 78 by 65, the number multiplied by n.
65
1.2 = n
120% = n Write 1.2 as a percent.
So, 78 is 120% of 65. Copyright 2012 Pearson Education, Inc.
Check this result.
Work Practice 12
Answers
10. 600 11. 10% 12. 140%