1. NS1.7 Solve problems that involve discounts, markups, commissions, and profit and compute simple and compound interest.
Also covered: NS1.3
California
Standards

2. A commission is a fee paid to a person who makes a sale
A commission is a fee paid to a person who makes a sale. It is usually a percent of the selling price. This percent is called the commission rate.
commission rate  sales = commission

3. Additional Example 1: Multiplying by Percents to Find Commission Amounts
A real-estate agent is paid a monthly salary of $900 plus commission. Last month he sold one condominium for $65,000, earning a 4% commission on the sale. How much was his commission? What was his total pay last month?
First find his commission.
4%  $65,000 = c commission rate  sales = commission
0.04  65,000 = c Change the percent
to a decimal.
2600 = c Solve for c.

4. Additional Example 1 Continued
A real-estate agent is paid a monthly salary of $900 plus commission. Last month he sold one condominium for $65,000, earning a 4% commission on the sale. How much was his commission? What was his total pay last month?
He earned a commission of $2600 on the sale.
Now find his total pay for last month.
$ $900 = $ commission + salary = total pay.
His total pay for last month was $3500.

5. Check It Out! Example 1
A car sales agent is paid a monthly salary of $700 plus commission. Last month she sold one sports car for $50,000, earning a 5% commission on the sale. How much was her commission? What was her total pay last month?
First find her commission.
5%  $50,000 = c commission rate  sales = commission
0.05  50,000 = c Change the percent to a decimal.
2500 = c Solve for c.

6. Check It Out! Example 1 Continued
A car sales agent is paid a monthly salary of $700 plus commission. Last month she sold one sports car for $50,000, earning a 5% commission on the sale. How much was her commission? What was her total pay last month?
The agent earned a commission of $2500 on the sale.
Now find her total pay for last month.
$ $700 = $ commission + salary = total pay.
Her total pay for last month was $3200.

7. Sales tax is the tax on the sale of an item or service
Sales tax is the tax on the sale of an item or service. It is a percent of the purchase price and is collected by the seller.

8. Additional Example 2: Multiplying by Percents to Find Sales Tax Amounts
If the sales tax rate is 6.75%, how much tax would Adrian pay if he bought two CDs at $16.99 each and one DVD for $36.29?
CD: 2 at $ $33.98
DVD: 1 at $ $36.29
$70.27 Total Price
 = Write the tax rate as a decimal and multiply by the total price.
Adrian would pay $4.74 in sales tax.

9. Check It Out! Example 2
Amy reserves a hotel room for $45 per night. She stays for two nights and pays a sales tax of 13%. How much tax did she pay?
$45  2 = $90 Find the total price for the hotel stay.
$90  0.13 = $ Write the tax rate as a decimal and multiply by the total price.
Amy spent $11.70 on sales tax.

10. Additional Example 3: Using Proportions to Find the Percent of Earnings
Anna earns $1500 monthly. Of that, $ is withheld for Social Security and Medicare. What percent of Anna’s earnings are withheld for Social Security and Medicare?
Think: What percent of $1500 is $114.75?
114.75
1500 n
100 =
Set up a proportion.
n  1500 = 100  Find the cross products.
1500n = 11, Simplify.

11. Additional Example 3 Continued
Anna earns $1500 monthly. Of that, $ is withheld for Social Security and Medicare. What percent of Anna’s earnings are withheld for Social Security and Medicare?
11,475
1500 n =
Divide both sides by 1500
n = 7.65
Simplify.
7.65% of Anna’s earnings is withheld for Social Security and Medicare.

12. Check It Out! Example 3
BJ earns $2500 monthly. Of that, $500 is withheld for income tax. What percent of BJ’s earnings are withheld for income tax?
Think: What percent of $2500 is $500?
500
2500 n
100 =
Set up a proportion.
n  2500 = 100  Find the cross products.
2500n = 50, Simplify.
50,000
2500 n =
Divide both sides by 2500.
n = 20
Simplify.
20% of BJ’s earnings are withheld for income tax.

13. Additional Example 4A: Finding Profit and Total Sales
A furniture store earns 30% profit on all sales. If total sales are $2790, what is the profit?
Think: What is 30% of 2790?
x = 0.30  Set up an equation.
x = 837
Multiply.
The profit is $837.

14. Additional Example 4B: Finding Profit and Total Sales
A furniture store earns 30% profit on all sales. If the store earns $10,044, how much are the total sales?
Think: 10,044 is 30% of what number?
Let s = total sales
10,044 = 0.30  s Set up an equation.
10,044
0.30
= Divide each side by 0.30.
0.30s
33,480 = s
Simplify.
The total sales are $33,480.

15. Check It Out! Example 4A
A retail store earns 40% profit on all sales. If total sales are $3320, what is the profit?
Think: What is 40% of 3320?
x = 0.40  Set up an equation.
Multiply.
x = 1328
The profit is $1328.

16. Check It Out! Example 4B
A furniture store earns 40% profit on all sales. If the store earns $5,680, how much are the total sales?
Think: 5,680 is 40% of what number?
Let s = total sales
5,680 = 0.40  s Set up an equation.
5,680
0.40
= Divide each side by 0.04.
0.40s
14,200 = s
Simplify.
The total sales are $14,200.