Connect Proportions and Percentages
Carla’s lunch at a restaurant costs $8.50. She wants to leave a 20% tip. How much should Carla leave for the tip?
$1.70
Write the equation in order to solve for a percent change (markup or markdown)
amount of change = percent change x original amount
What is a markup and markdown? Why do they exist?
A markup is the amount added to the cost price of a product to determine its selling price. Markups exist to ensure that businesses cover their costs (such as production, labor, and overhead) and make a profit.
A markdown is a reduction in the original selling price of a product. Markdowns exist because businesses need to clear out old or excess inventory to make room for new products.
Write the equation in order to solve a simple interest problem.
interest = interest rate x principal.
Write the percent error equation.
amount of error = percent error x actual value
A factory produces lightbulbs. During an inspection, it is found that out of 1,280 light bulbs, 64 are defective. What percent of the lightbulbs are defective?
5%
The price of a pencil increases from $0.50 to $0.60. What is the percent increase?
20%
A camping store pays a wholesale price of $24.50 for a fishing rod and sells it for $31.85. What is the percent markup?
30%
A savings account with an annual interest rate of 1.25% is opened with $800. If no additional deposits or withdrawals are made, what will be the account balance at the end of the year?
$810
A student measures the length of a pencil to be 15.5 cm, but the actual length is 16 cm. What is the percent error in the student's measurement?
3.13%
Manuel buys a shirt that costs $24. The tax rate is 6%. He wants to find the amount of tax x he will need to pay on the shirt. Write a percent proportion that can be used to solve the problem.
6/100 = x/24
A pair of shoes originally cost $80 but is now on sale for $60. What is the percent decrease?
25%
The wholesale cost of a dining room table at a furniture store is $1,215.80. The markup for the table is 30%. What is the selling price of the dining room table?
$1,580.54
A savings account is opened with $650. No additional deposits or withdrawals are made and the balance at the end of the year is $657.80. What is the annual interest rate?
1.2%
A student measures the temperature of a solution to be 58.2°C, but the actual temperature is 60°C. What is the percent error?
3%
Nina says that to find the amount of tax on a coat that costs $80 with a tax rate of 8%, she can solve the proportion:
8/80 = x/100
Is Nina correct? If not, fix the proportion.
your reasoning.
No, she is not correct. The correct proportion is:
8/100 = x/80
A company’s sales increased from $500,000 to $750,000. What is the percent increase?
50%
A washing machine is on clearance for 30% off. If the sale price of the washing machine is $395.49, what was the original price?
$565.70
Samantha opens a savings account with $500. The bank offers an annual interest rate of 3%. What will be the balance of her account at the end of the year?
$515
A student measures the mass of a rock to be 82.3 g, but the true mass is 80 g. What is the percent error?
2.88%
Jaquim buys a mattress. The delivery fee is $44, which is 8% of the cost of the mattress.
Part a: Create a proportion to solve the problem.
Part b: What is the cost of the mattress?
Part a:
8/100 = 44/x
Part b: $550
A tech company's stock price increased from $92.50 to $143.75. What is the percent increase?
55.56%
A store buys a sofa for $1,200 and applies a 40% markup. After a few months, the store decides to put the sofa on sale with a 25% markdown from its original selling price. What is the final sale price of the sofa?
$1,260
Brandy opens a savings account with $600 . Bank A offers an annual interest rate of 2.5%. Bank B offers an annual interest rate of 2.2% . What is the difference between the balances of Bank A and Bank B after one year?
Bank A: $615
Bank B: $613.20
Difference: $1.80
A student measures the width of a football field to be 99.8 meters, but the true width is 100 meters. What is the percent error?
0.2%