Basic Mathematics for College Students

6.3 Applications of Percent 545

EXAMPLE (^8) Shoe Sales Use the information in the advertisement
shown on the previous page to find the amount of the discount on the pair of men’s
basketball shoes. Then find the sale price.
StrategyWe will identify the discount rate and the original price of the shoes and
use a formula to find the amount of the discount.
WHYThen we can subtract the discount from the original price to find the sale
price of the shoes.
SolutionFrom the advertisement, we see that the discount rate on the men’s
shoes is 25% and the original price is $89.80.
This is the amount of
discount formula.
Substitute 25% for the
discount rate and $89.80 for
the original price.
Write 25% as a decimal:
25% 0.25.
Do the multiplication.
The discount on the men’s shoes is $22.45. To find the sale price, we use subtraction.
This is the sale price formula.
Substitute $89.80 for the
original price and $22.45 for
the discount.
Do the subtraction.
The sale price of the men’s basketball shoes is $67.35.

$67.35

 $89.80  $22.45

Sale priceoriginal pricediscount

$22.45

0.25$89.80

 25%  $89.80

Amount of discountdiscount rateoriginal price

Self Check 8

SUNGLASSES SALESSunglasses,

regularly selling for $15.40, are

discounted 15%. Find the

amount of the discount. Then

find the sale price.

Now TryProblem 41

89.80

 0.25

44900

179600

22.4500

89.8

7

0

10

 22.45

67.35

EXAMPLE (^9) Discounts Find the discount rate on the ladies’ cross trainer
shoes shown in the advertisement on the previous page. Round to the nearest one
percent.
StrategyWe will think of this as a percent-of-decrease problem.
WHYWe want to find what percent of the $59.99 original price the amount of
discount represents.
SolutionFrom the advertisement, we see that the original price of the women’s
shoes is $59.99 and the sale price is $33.99. The discount (decrease in price) is found
using subtraction.
Use the formula:
Amount of discount original price sale price.
The shoes are discounted $26. Now we find what percent of the original price the
$26 discount represents.
This is the amount of
discount formula.
Substitute 26 for the amount
of discount and $59.99 for the
original price. Let xrepresent
the unkown discount rate.
We can drop the dollar signs. To undo the multiplication by 59.99
and isolate xon the right side of the equation, divide both sides
by 59.99.

26

59.99



x59.99

59.99

26  x  $59.99

Amount of discountdiscount rateoriginal price

$59.99$33.99$26

Self Check 9

DINING OUTAn early-bird special

at a restaurant offers a $10.99

prime rib dinner for only $7.95 if

it is ordered before 6 P.M. Find

the rate of discount. Round to

the nearest one percent.

Now TryProblem 45