1. 05 – 04c Percents

2. Percent of Decrease or increase
Old
New
New – Old
Old
Negative answer => Decrease
Positive answer => Increase

3. Percent of Decrease or increase
August hosted two dinner parties for his friends. Twenty guests attended the first party, and twenty-nine guests attended the second party. What is the percentage increase of the number of guests from the first party to the second party?
New – Old
Old
Negative answer => Decrease
Positive answer => Increase

4. Sales Tax
An item is priced at $ If the sales tax is 4%, what does the item cost including sales tax?
Multiply price by sales tax (decimal) $13.24 × 0.04 = $0.53
(round to nearest penny)
Now, add the tax to the full price. $ $0.53 = $13.77

5. First, find the total for the hourly charges.
Bill plus tip
Dave rented a limousine for his wife's birthday. The hourly rate is $80. They used the limousine for 4 hours, plus Dave gave the driver a 20% tip. How much did he spend in total for the hourly charges plus tip?
First, find the total for the hourly charges.
hourly rate × hours used = $80 × 4 = $320
Next, determine the tip on that total.
20% of $320 = 0.2 × $320 = $64
Finally, find the total of the hourly charges plus the tip.
$320 + $64 = $384

6. Interest
Tonya took out a loan to help pay for her house. She borrowed $30,000 for 15 years at a yearly simple interest rate of 5%. How much interest will she end up paying the bank?
The formula for computing simple interest is shown below,
where p is the principal (starting) amount,
r is the interest rate (in decimal form),
and t is the time (in years).
I = prt
The principal is $30,000, the time is 15 years, and the interest rate is 5%, or 0.05. I
 = 
($30,000)(0.05)(15 yr)
$22,500

7. Interest
Tonya took out a loan to help pay for her house. She borrowed $30,000 for 15 years at a yearly simple interest rate of 5%. How much interest will she end up paying the bank?
The formula for computing simple interest is shown below,
where p is the principal (starting) amount,
r is the interest rate (in decimal form),
and t is the time (in years).
I = prt
The principal is $30,000, the time is 15 years, and the interest rate is 5%, or 0.05. I
 = 
($30,000)(0.05)(15 yr)
$22,500

8. Interest
Tonya took out a loan to help pay for her house. She borrowed $30,000 for 15 years at a yearly simple interest rate of 5%. How much interest will she end up paying the bank?
The formula for computing simple interest is shown below,
where p is the principal (starting) amount,
r is the interest rate (in decimal form),
and t is the time (in years).
I = prt
The principal is $7,000, the rate is 3%, or 0.03, and the interest is $1,050.

9. Interest
Tonya took out a loan to help pay for her house. She borrowed $30,000 for 15 years at a yearly simple interest rate of 5%. How much interest will she end up paying the bank?
The formula for computing simple interest is shown below,
where p is the principal (starting) amount,
r is the interest rate (in decimal form),
and t is the time (in years).
I = prt
The principal is $7,000, the rate is 3%, or 0.03, and the interest is $1,050.

10. Interest
Bert is planning to open a savings account that earns 1.6% simple interest yearly. He wants to earn exactly $288 in interest after 3 years. How much money should he deposit?
The formula for computing simple interest is shown below,
where p is the principal (starting) amount,
r is the interest rate (in decimal form),
and t is the time (in years).
I = prt
The desired interest is $288, the time is 3 years, and the interest rate is 1.6%, or

11. Next, find the percentage of school days she attended.
Find a percent
Holly missed 6 of 180 school days this year. Approximately what percent of school days was Holly in attendance?
First, determine how many school days Holly attended.
= 174
Next, find the percentage of school days she attended.
174 ÷ 180 =
= 97%

12. Next, find how many of the blue ones were damaged.
Damaged items
Kathleen had a bag of candy-coated chocolates. Of the 60 candies in the bag, 20% were red, 30% were orange, 30% were green, and 20% were blue. Of the blue ones, 10% had a damaged candy coating. Approximately how many of the blue ones had a damaged candy coating?
First, determine how many of the candies were blue.
20% of 60 = 0.2 × 60 = 12
Next, find how many of the blue ones were damaged.
10% of 12 = 0.1 × 12 = 1.2
Approximately 1 of the blue ones had a damaged candy coating.

13. First, find the total cost for service and repairs.
Next, determine the total after the 10% discount.
coupons
Nathan took his car in for service and repairs. He had a coupon for 10% off. Original Prices Labor $ Parts $ Other $67.18 Which amount is closest to Nathan's total costs after the 10% discount and including 7% sales tax? [Assume tax is applied after the discount is applied.]
First, find the total cost for service and repairs.
$ $ $67.18 = $752.58
$ ($752.58)
 = 
$ $75.26
$677.32

14. Coupons cont.
Finally, apply the 7% sales tax. $ ($677.32) = $ $47.41 = $724.73

15. (1 + 30%). Convert 30% to 0.3. $364.00 ÷ (1 + 0.3) = $280.00
Percents
The value of a professional basketball player's autograph rose 30% in the last year. It is now worth $ What was it worth a year ago?
(1 + 30%). Convert 30% to 0.3.
$ ÷ ( ) = $280.00

16. % of discount
Jessica purchased a sapphire bracelet during the Jewelry Emporium's Semi- Annual Clearance Sale. If Jessica paid $ for the bracelet and the original price is $260.00, how much of a discount did she receive?
Original Price - Discount
 = 
Sale Price
$ ($ × p)
$182.00
-$260.00p
 = 
-$78.00
$260.00p
$78.00 p
$78.00 ÷ $260.00
0.3
30%

17. Deposit, how much is still owed
Molly is having her birthday party at Pizza Party Palace. The costs involved are listed below. Pizza Party Palace requires a 20% deposit prior to the date of the event. If the deposit has been paid, how much is still owed for Molly's party?
First, find the total of all party costs.
$200 + $100 + $60 = $360 •
Food & Drink
$200
Game Tokens
$100
Other
$60
Next, find 20% of $360.
20% of $360 = 0.2 × $360 = $72
$360 - $72 = $288

18. 6-ounce $9.95 8-ounce $12.95 11-ounce $15.95
Meals and gratituity
Brad had a small gathering at a local steakhouse. The steakhouse offers three dinner platters which vary by size and price. They ordered 4 of the 6-ounce platters, 2 of the 8-ounce platters, and 2 of the 11-ounce platters.
Steak Platter Prices
If a gratuity of 18% was added to the bill, which of the following is closest to the total of the steak platters and gratuity, ignoring sales tax? •
6-ounce
$9.95
8-ounce
$12.95
11-ounce
$15.95
First, find the total cost for all dinner platters.
4($9.95) + 2($12.95) + 2($15.95)
$ $ $31.90 = 
 = 
$97.60

19. Next, determine the 18% gratuity. 18% of $97.60 = 0.18 × $97.60 $17.57
Meals and gratituity
Brad had a small gathering at a local steakhouse. The steakhouse offers three dinner platters which vary by size and price. They ordered 4 of the 6-ounce platters, 2 of the 8-ounce platters, and 2 of the 11-ounce platters.
Steak Platter Prices
If a gratuity of 18% was added to the bill, which of the following is closest to the total of the steak platters and gratuity, ignoring sales tax?
Next, determine the 18% gratuity.
18% of $97.60 = 0.18 × $97.60
$17.57
Finally, find the sum of the dinner platters plus the gratuity.
$ $17.57 = $115.17

20. Next, determine how much total free time he has each week.
% of time
In his free time, Gary spends 12 hours per week on the Internet and 7 hours per week playing video games. If Gary has five hours of free time per day, approximately what percent of his free time is spent on the Internet and playing video games?
First, find the total time Gary spends on the Internet and playing video games per week.
= 19
Next, determine how much total free time he has each week.
5 × 7 = 35
Finally, determine what percent of his free time is spent on the Internet or playing video games.
19 ÷ 35 =
Gary spends approximately 54% of his free time on the Internet and playing video games.

21. Percents
Brian has reduced his cholesterol level by 14% by following a strict diet and regular exercise. If his original level was 300, what is his cholesterol level now?

22. First, determine Sandy's earnings based on her hourly wage.
Commission
Sandy works at a clothing store. She makes $9 per hour plus earns 15% commission on her sales. She worked 70 hours over the last two weeks and had a total of $1,822 in sales before taxes. Which of the following is closest to how much she will earn in hourly wages and commission for those two weeks?
First, determine Sandy's earnings based on her hourly wage.
hours worked × hourly wage = 70 × $9 = $630
Next, determine her commission on her total sales.
15% of her total sales = 0.15 × $1,822 = $273.30
Finally, find the sum of her hourly wages plus commission.
$630 + $ = $903.30

23. The End