Basic % Problems
% of Change
Tax/Tips/Discounts/
Markups
Simple Interest
Scale Factor
100
What is 112% of 14?
15.68
100
What is the formula used to calculate percent of change?
amount of change/original amount
100
You buy a candy bar that costs $0.99. There is 6.5% tax added to your total. How much will you pay for the candy bar?
$1.05
100
What is the formula to calculate simple interest, and what does each letter represent?
I = PRT; I= (simple) interest, P= principle, R = rate, T = time
100
Rectangle A has been redrawn as Rectangle B. If the length of Rectangle A is 10cm and the lenth of Rectangle B is 4cm, what is the scale factor?
2/5
200
What is 1/5% of 90?
0.18
200
You used to have $500 in your bank account. You now have $640. What is the percent of change? (Be sure to include increase or decrease.)
28% increase
200
You and your family go out for dinner. The bill comes to $65.42. There is 7% tax added. Your family pays for dinner, then decides to leave a 19% tip in cash on the table (calculated post tax.) How much did your family pay for dinner?
$65.42 + $4.58 tax = $70.00 + $13.30 tip = $83.30 total
200
Calculate the simple interest if you borrow $700 for 3 years and are given an interest rate of 11.25%.
$236.25 simple interest
200
Rectangle A has been redrawn as Rectangle B. If the length of Rectangle A is 10cm and the lenth of Rectangle B is 4 meters, what is the scale factor?
40 (Rectangle B is 40 times larger).
300
Kevin spent $80 on a pair of shoes. The money he spent was 60% of his savings. How much money was in his savings account before he went shopping?(Round to the nearest penny.)
$133.33
300
You thought there were 400 marbles in a jar. There were only 298. What was your percent of error? (Round to nearest tenth.)
34.2% error
300
You go to Target and place $205 worth of merchandise in your cart. You get to the register and discover you have a coupon for 15% off your purchase. After the discount is applied, you notice that there is 5.5% sales tax added to your bill. How much more money would you have paid if you HADN'T used the coupon?
$183.83 with coupon applied, $216.28 without coupon = $32.45 more without the coupon
300
Calculate the total amount of money in your savings account today if you placed $1,000 in the account 9 months ago and accrued interest at a rate of 0.5%.
$3.75 interest + $1,000 = $1,003.75 in the account
300
First find the length you would need for the scale drawing of the object. Then find the scale factor. a room 15 feet long; 1 inch = 6 feet
2.5 inches for scale drawing; 1/72 scale
400
Carolina answered 71 problems of a 75 question test. About what percent does she still have left to answer?
About 5%.
400
Josh went from eating 7 Jolly Ranchers each day to eating 3. Kevin went from eating 54 Jolly Ranchers each day to eating 85. (Yes, Kevin has a Jolly Rancher eating problem. He knows.) Who experienced the bigger percentage of change? Prove it.
Kevin (57.4% increase) not Josh (57.1% decrease)
400
Old Navy manufactures canvas bags for $0.35 each. They apply a 560% markup before they place a price tag on each bag at the store. How much would you end up paying for a bag?
$2.31
400
Find the interest rate. You borrowed $800 and paid it back in 2 years. You accrued $112 in interest charges.
7% interest rate
400
First calculate the length you would need to make the scale model. Then calculate the scale factor. A tower is 80 meters tall; 0.8 centimeter = 1 meter.
64 cm tall model; 1/125 scale factor
500
April makes $12 an hour to babysit. She only makes 1/2% of what her grandfather makes per hour at his company. How much money does her grandfather make per hour? (He has a really good job, apparently!)
$200 per hour
500
If the side lengths of a 4cm x 5 cm rectangle are tripled, describe the percent of change of the resulting AREA.
800% increase
500
What percentage is the tax if you paid $55 for a pair of pants that cost $49.50 before tax was added?
10% tax
500
How long has your money been in your bank account if you initially deposited $28, the account has a 4% interest rate, and have accrued $3.92 in interest? (Express your answer in MONTHS.)
42 months (3.5 years)
500
A blueprint shows a kitchen that is 1/4 in. x 3 in. If the scale on the blueprint says that 1/2 in. = 5 feet, what is the actual area of the kitchen?
2.5 ft. x 30 ft. = 75 sq. ft.
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