Percent Review
15% of 45
6.75
What is the formula for percent error?
¿Cuál es la fórmula para el error porcentual?
|actual - experimental||. x 100
actual
P = 400
r = 0.15
t = 3
What is I?
180
Rosa and her friends are eating out for dinner. The bill was $45.80. They want to leave a 20% tip. How much should they leave for tip? What would be the total?
$9.16, $54.96
100 reduced to 80. What percent has it decreased by?
20% decrease
What percent of 340 is 85?
25%
The report said the carpark held 240 cars, but we counted only 200 parking spaces. What was the percent error?
20%
I = 49.92
P = 130
t = 4
r = 9.6%
What is the total?
179.92
Lauren went to a restaurant with her friends. The bill was $45. The sales tax was 9% of the bill and they left a 15% tip (before tax). How much do they leave in total?
total: $55.80
tax: $4.05
tip: 6.75
$12 increases to $15. What is the percent change?
25% Increase
40 is 32% of what number?
125
Joey is measuring the amount of time it takes for a frisbee to fly through the air. He uses a stopwatch to time it and finds that it takes 4.82 seconds. If it actually takes 5.05 seconds, then what is the percent error in Joey’s measurement to the nearest tenth of a percent?
4.6%
Isabella deposited $500 into a savings account at a local bank that earned 5.5% interest per year. How much interest does she earn per year?
Isabella earns $27.50 per year in interest from her local bank.
A real estate agent sold a house for $315,000 last week. If her commission is 1.25% of the selling price of the home, find the amount of her commission.
$3,937.50
45 becomes 70. What is the percent of change?
55.56% increase
Out of 380 cars passing on the highway, 35% are speeding. How many cars are speeding?
133
Joshua uses his thermometer and finds the boiling point of ethyl alcohol to be 75o C. He looks in a reference book and finds that the actual boiling point of ethyl alcohol is 80oC. What is his percent error?
6.25%
To buy a computer, Raquel borrowed $3,000 at 9% interest for 4 years. How much money did she have to pay back in all?
$4,080.00.
Joshua is buying a pair of sneakers that originally cost $120. He uses a coupon for 35% off the original price. After the coupon is applied, Joshua will be charged 8.5% sales tax on the sneakers. What is the final amount Joshua will pay for the sneakers?
$84.63
A persons salary changes from $2,400 a month to $3,000 a month. What is the percent change?
25% increase
75% of the seventh graders are right-handed. If 96 7th graders are right-handed, how many total 7th graders are there?
128
The Handbook of Chemistry and Physics lists the density of a certain liquid to be 0.7988 g/mL. Taylor experimentally finds this liquid to have a density of 0.7925 g/mL. The teacher allows up to 0.5% error to make an “A” on the lab. Did Fred make an “A”? Prove your answer.
No, he got a 0.79% which is greater than 0.5%
When Kevin bought a new office phone, he borrowed $1,200 at a rate of 18% for 9 months. How much interest did he pay?
Kevin paid $162.00 in interest.
This January, Laurie sold a house for $562,000. She charges her customers a commission fee of 2.5% on the selling price of the house. She also makes a monthly salary of $35,000. How much money did she earn in total this month?
$49,050
You own 45 books. If you donated 12 books to charity. By what percent has your number of books changed?
26.67% decrease