1. Percents In Algebra County

2. Things to remember: Of means multiply To convert a decimal to a percent, move the decimal two places to the right. To convert a percent to a decimal, move the decimal two places to the left. To convert a percent to a fraction, divide by 100. 45% of 30 45% 30% 51%

3. Use the basic equation below to solve percent problems: Example 1: What is 50% of 16? orUse a calculator to find the answer. Example 2: What percent of 14 is 8? If I spend 35% of my money, how much did I not spend? 65%. With percents, 100% is an important concept. Concept:

4. Example 3: (Easy) If 20% of p is 10, then 10% of p is A.2 B.4 C.5 D.8 E.14

5. Example 4: (Medium) Mabel agreed to pay the tax and tip for dinner at a restaurant with her four friends. Each of the friends paid an equal part of the cost of the dinner, which was $96. If the tax and tip together were 20% of the cost of the meal, Mabel paid how much less than any one of her other friends? A.$2.40 B.$4.80 C.$9.20 D.$19.20 E.$24.00 Mabel’s friends paid each. This makes $24 each. Mabel paid 20% of 96. Mabel $24 – $19.20 less than the others, which is $4.80

6. Example 5: (Hard) If 200% of 40% of x is equal to 40% of y, then x is what percent of y? A. 10% B. 20% C. 30% D. 50% E. 80% (Reduce) One-half is 50%.

7. Example 6: (Medium) A store owner buys a pound of grapes for 80 cents and sells it for a dollar. What percent of the selling price of grapes is the store owner’s profit? A. 10% B. 20% C. 25% D. 40% E. 80%

8. Example 7: (Hard) On the first test of the semester, Barbara scored a 60. On the last test of the semester, she scored a 75. By what percent did Barbara’s score improve? A. 12% B. 15% C. 18% D. 20% E. 25% (Reduce)

9. Example 8: (Hard) Randy’s chain of used car dealerships sold 16,400 cars in 1998. If the chain sold 15,744 cars in 1999, by what percent did the number of cars sold decrease? A. 1% B. 4% C. 11% D. 40% E. 65%

10. Percent of increase or decrease is used in a lot of real life applications. For instance, an employee is expecting a 3% raise for next year. This means his new salary is 103% of what it was. Similarly, if his salary decreased 5%, he is making 95% of what he made last year. Example 9: (Hard) Mr. White deposited a sum of money in an account at 4% annual interest. If his sum increased to $546 at the end of the year, how many dollars had he originally deposited? A. $525 B. $515 C. $520 D. $502.50 E. $510 The amount of money he has at the end of the year is 104% of what he started with.

11. Percent of increase. Example 10: Erin received a raise at her job from $14 per hour to $17 per hour. What is the percent increase of her raise?

12. Keep Driving in Algebra County, even though sometimes the work is hard.