Basic Mathematics for College Students

6.3 Applications of Percent 535

100. Explain why each of the following problems is easy
     to solve.
     a. What is 9% of 100?
     b. 16 is 100% of what number?
     c. 27 is what percent of 27?


101. When solving percent problems, when is it best to
     write a given percent as a fraction instead of as a
     decimal?


102. Explain how to identify the amount, the percent, and
     the base in a percent problem.

REVIEW

103. Add:


104. Evaluate:


105. On the number line, which is closer to 5:
     the number 4.9 or the number 5.001?


106. Multiply:


107. Evaluate:


108. Evaluate the formula d 4 tfor t 25.

(0.2)^3

34.54641,000

164  319

2.78 6 9.090.3

SECTION 6.3

Applications of Percent

In this section, we discuss applications of percent. Three of them (taxes, commissions,
and discounts) are directly related to purchasing. A solid understanding of these
concepts will make you a better shopper and consumer. The fourth uses percent to
describe increases or decreases of such things as population and unemployment.

Objectives

1 Calculate sales taxes, total cost,

and tax rates.

2 Calculate commissions and

commission rates.

3 Find the percent of increase or

decrease.

4 Calculate the amount of

discount, the sale price and the

discount rate.

1 Calculate sales taxes, total cost, and tax rates.

The department store sales receipt shown below gives a detailed account of what
items were purchased, how many of each were purchased, and the price of each
item.

The receipt shows that the $56.35 purchase price (labeled subtotal) was taxed at
a rate of 5%. Sales tax of $2.82 was charged.
This example illustrates the following sales tax formula. Notice that the formula
is based on the percent equation discussed in Section 6.2.

Department Store #612

Bradshaw’s

4

1

1

3

2

@

@

@

@

@

1.05

1.39

24.85

2.25

9.58

GIFTS

BATTERIES

TOASTER

SOCKS

PILLOWS

$ 4.20

$ 1.39

$24.85

$ 6.75

$19.16

SUBTOTAL

SALES TAX @ 5.00%

TOTAL

$56.35

$ 2.82

$59.17

The sales tax rate

The purchase price of

the items bought

The sales tax on the

items purchased

The total cost