Percent Applications Study Guide

Percent Applications Study Guide

Make sure to take notes in your notebook. You can use them on your test tomorrow.

​The Percent Proportion

​The percent proportion is shown to the right. It is percent over 100 equals part over whole.

​

​In the example, we can see that 3 is 60% of 5.

​

3 is the part. 5 is the whole.

​60% is the percent and 100 represents 100% which is always equal to 1 whole.

Multiple Choice

What does it mean if you have 100% of something?

• you have none of it

• you have half of it

• you have the entire amount

• you have more

Multiple Choice

In the question,

"35 is what percent of 40?"

What is the 40?

• Part

• Whole

• Percent

• Nothing

To calculate percent of a number:

Turn your percent into a decimal and multiply by a whole number.

​To turn your percent into a decimal you can move the decimal to the left twice OR divide the percent by 100.

Multiple Choice

Write 0.673 as a percent.

• 6.73%
• 67.3%
• 673%

Multiple Choice

Write 16.33% as a decimal.

• 0.1633
• 1.633
• 0.163

Multiple Choice

Write 283% as a decimal.

• 28.3
• 0.0283
• 2.83

Multiple Choice

What is 11% of 15?

• 1.65
• 1.56
• 2.5

Multiple Choice

What is 15% of 82?

• 12.3
• 123
• 1.23

Multiple Choice

The middletown Zoo has 130 different exhibits.  Of those 130 exhibits, 30% of them contain birds.  How many exhibits contain birds?

• 49
• 39
• 60
• 25

​Discounts

​To calculate the amount saved or the discount:

​Turn the percent into a decimal and multiply by the original price.

​

​If the question asks for the new or sale price:

​Subtract the discount amount from the original price.

Multiple Choice

 If you receive 25% off an item costing $22.00, how much money do you save?

• $ 5.50
• $ 4.25
• $6.00
• $7.35

Multiple Choice

Discount is ____________ from the price.

• added
• divided
• subtracted
• Ms. Golino is awesome

Multiple Choice

In a video store, a DVD that sells for $15 is marked 10% off. What is the amount of discount?

• 1.00
• 1.50
• 16.50
• 13.50

Multiple Choice

You want to buy a shirt.  The original price was $27, and the sale says 25% off.  How much will pay for the shirt?

• 0.25
• 33.75
• 6.75
• 20.25

Multiple Choice

Regular price: $174. Discount: 40%. Find the sale price. Round to nearest cent if necessary.

• $104.40
• $140.40
• 104.4
• 69.6

Multiple Choice

Alicia went to the local farmer's market to buy some fresh produce. She bought carrots for 35% off the original price of $7.40. How much did Alicia pay for the carrots?

• 4.81
• 2.59
• 9.99
• 3.50

Working backwards to calculate the percent discounted or marked up:

(​Amount of discount/markup divided by the original price) x 100.

To calculate:

Subtract the original price - new price.

Then, divide your answer by the original price.​

​Multiply that answer by 100.

​(ALWAYS CALCULATE DISCOUNTS BEFORE TAX. TAX IS CALCUATED USING SALE PRICE.)

​Example: Adam bought a T-shirt that was originally $15 for $12. What percent was this shirt discounted?

​15-12= 3

​3 divided by 15 = 0.2

​0.2 x 100 = 20%

​

​The shirt was discounted 20% off.

Multiple Choice

Find the percent of change if the original cost was $5 and the new cost is $1. 

• Increase $4
• Decrease $4
• Decrease 80%
• Decrease 400%

Multiple Choice

The original price of your backpack was $35. This month the price is $42. What is the percent change?

• 20%

• 35%

• 17%

• 14.6%

Sales Tax and Tips:​

To calculate the amount of tax or tip:​

​Turn the percent into a decimal and multiply by the original price.

​

​If the question asks for the new or final price:

Add the tax or tip amount to the original price.

Multiple Choice

Tax on a $12, 985 car is 6%.  What is the amount of tax?

• 13,764.10
• 908.95
• 14,023.8
• 779.10

Multiple Choice

You got good service at a restaurant so you wanted to leave a 25% tip.  If the meal was $23.95, what was your amount of tip?

• 5.99
• 29.94
• 4.79
• 28.74

Multiple Choice

Tax on a $12, 985 car is 6%.  What is the total price of the car?

• 13,764.10
• 908.95
• 14,023.8
• 779.10

Multiple Choice

A pair of awesome skinny jeans costs $25, but it is on sale for 25% off.  Score!  If tax is 8%, what is the total cost?

• 18.75
• 20.25
• 27
• 22.50

Income Tax​

Income tax is tax that has to be paid to the government based on the amount of income you make. ​

​To calculate income tax:

​Turn your percent into a decimal and multiply by the amount of income made in one year.

Multiple Choice

Vickie makes $40,000 annually.  If she pays 20% in income tax, what is the amount of income tax she will pay?

• 8000
• 80000
• 2000
• 1200

Multiple Choice

Peter is a college professor.  His annual salary is $112,000.  If he has to pay 25% income tax what is the amount of tax he will pay?

• 30000
• 28000
• 25000
• 22000

Simple Interest​

I = PRT

Interest = Principal x Rate x Time

Interest is the extra money earned or paid.

Principal is the original amount invested or borrowed.

Rate is the percentage.​

​Time is the amount of time in years.

​If you know the interest and need to find one out of P, R, or T, divide the interest by the other two variables.

Multiple Choice

Emilio borrows $1200 from a bank with 8% simple interest per year.  How much will he have to pay back total in 2 years?

• $150
• $192
• $1350
• $1392

Multiple Choice

Principal = $500
Interest rate =5%
Time = 5 years
What is the interest earned?

• 95
• 105
• 125
• 135

Multiple Choice

The simple interest formula is I=Prt.  What does the t represent?

• Principle
• Interest
• Time, in hours
• Time, in years

Multiple Choice

Convert 18 months to years. 

• 18 Years
• 1.5 Years
• .18 Years
• You cannot change it to years.

Multiple Choice

What does the "I" in the interest formula stand for?

• Important
• Interest
• Internet
• Igloo

Multiple Choice

The rate is given as a percent (%).  Before using it in the simple interest formula, you must first convert it to a______.

• fraction
• decimal
• ratio
• dollar amount

Multiple Choice

The simple interest formula is I=Prt.  The P represents the principle.  The principle is ___________________.  

• the amount of money borrowed or deposited
• the percent interest for his year
• the amount taxed
• the amount the bank owes you for being a customer at their bank

Multiple Choice

Jack deposited $1,400 in his bank account.  After 3 years, the account earned $294 in interest.  Find the simple interest rate.

• 5%
• 8%
• 7.25%
• 7%

A rebate is money you receive back after making a purchase.

​For example, a new X-Box is on sale. The store is offering a $75 mail-in rebate. That means that you go to the store and pay full price and then they will mail you $75 a few weeks later.

​Because rebates come so late they are always subtracted LAST, after discounts, tips, and taxes.

Multiple Choice

Ariel is buying new shoes. They are $40, and there is a 10% off discount. There is also a 5% tax. Ariel also has a coupon for a $10 mail in rebate. How much will Ariel pay for the shoes after discounts, taxes, and rebates?

• $25.00

• $27.80

• $37.80

• $15.00