Math OER Zoom Room Jamboard Lectures Textbook

# Math OER Turn In Problems  Mad Science Percentages

The greatest reward for a student is not a good grade. It is the willingness of his teacher to listen to him.

- Nikolay Konstantinov

You attempted the ten exercises for this topic. Those problems did not have an answer key. Use this form to ask me how well you did.

Before using this page, you should have your homework completed on paper. This page is only for submitting your homework. To be short and concise it lacks any diagrams, pictures, or tables needed to work the problems.

Answer every question. Then use the button at the bottom of the page to create a code by processing your answers. Copy-and-paste the code into an e-mail.

1. What is 25% of 228?

0.57 5.7 57 5,700

2. What is 40% of 750?

30 300 3,000 30,000

3. The price tag (before sales tax) on an item says \$100. The sales tax rate is 5%. What is the total price (including tax)?

\$5 \$105 \$500 \$2,000

4. During a sale, a dress decreased in price from \$90 to \$72. What was the percent of decrease?

20% 80% 120% 125%

5. An investment increases in value from \$200 to \$216. What is the percent increase?

8% 16% 32% 34.56%

6. A pinball machine that normall sells for \$3,999 is on sale for \$3,150. What is the rate of discount?

\$849 21.2% 98.5% 101.6%

7. Bluebeard has a balance of \$1,834.90 on a credit card with an annual percentage rate of 22.4%. This month's minimum payment is \$36.70. How much less than this minimum payment is the interest? (In other words, if he only pays the minimum payment, how much goes "past" the interest to pay off his principal?)

\$2.45 \$3.74 \$4.40 \$32.59

8. Find the simple interest for a 2 year loan of \$8,000 at a simple interest rate of 12%.

\$192 \$230.40 \$960 \$1,920

9. Find the simple interest for a 2 month loan of \$8,000 at a simple interest rate of 9.42%.

\$62.80 \$125.60 \$753.60 \$1,507.20

10. A store takes out a ninety day loan for \$6,500 at 5.25% simple interest. What is the total amount due after ninety days?

\$84.14 \$341.25 \$6,584.14 \$6,841.25