A pharmacist wishes to mix a solution that is 2% minoxidil. She has on hand 50 mL of a

Answer each question. See Example 1 and the Problem-Solving Hint preceding Example 4. How much pure alcohol is in 150 L of a 30% alcohol solution?

Answer each question. See Example 1 and the Problem-Solving Hint preceding Example 4. How much pure acid is in 250 mL of a 14% acid solution?

Answer each question. See Example 1 and the Problem-Solving Hint preceding Example 4. If $25,000 is invested for 1 yr at 3% simple interest, how much interest is earned?

Answer each question. See Example 1 and the Problem-Solving Hint preceding Example 4. If $10,000 is invested for 1 yr at 3.5% simple interest, how much interest is earned?

Answer each question. See Example 1 and the Problem-Solving Hint preceding Example 4. What is the monetary value of 35 half-dollars?

Answer each question. See Example 1 and the Problem-Solving Hint preceding Example 4. What is the monetary value of 283 nickels?

Solve each percent problem. Remember that base rate percentage. The population of New Mexico in 2007 was about 1,917,000, with 44.4% Hispanic. What is the best estimate of the Hispanic population in New Mexico? (Source: U.S. Census Bureau.) A. 850,000 B. 85,000 C. 650,000 D. 44,000

Solve each percent problem. Remember that base rate percentage. The population of Alabama in 2007 was about 4,628,000, with 26.5% represented by African-Americans. What is the best estimate of the African-American population in Alabama? (Source: U.S. Census Bureau.) A. 600,000 B. 750,000 C. 1,200,000 D. 1,500,000

Solve each percent problem. Remember that base rate percentage. The graph shows the breakdown, by approximate percents, of the colors chosen for new 2007 model-year full-size and intermediate cars sold in the United States. If approximately 3.8 million of these cars were sold, about how many were each color? (Source: Wards Communications.) (a) White (b) Silver (c) Red

Solve each percent problem. Remember that base rate percentage. An average middle-income family will spend $221,190 to raise a child born in 2008 from birth to age 18. The graph shows the breakdown, by approximate percents, for various expense categories. To the nearest dollar, about how much will be spent to provide the following? (a) Housing (b) Food (c) Health care

Suppose that a chemist is mixing two acid solutions, one of 20% concentration and the other of 30% concentration. Which concentration could not be obtained? A. 22% B. 24% C. 28% D. 32%

Suppose that pure alcohol is added to a 24% alcohol mixture. Which concentration could not be obtained? A. 22% B. 26% C. 28% D. 30%

Work each mixture problem. See Example 2. How many liters of 25% acid solution must a chemist add to 80 L of 40% acid solution to obtain a solution that is 30% acid?

Work each mixture problem. See Example 2. How many gallons of 50% antifreeze must be mixed with 80 gal of 20% antifreeze to obtain a mixture that is 40% antifreeze?

Work each mixture problem. See Example 2. A pharmacist has 20 L of a 10% drug solution. How many liters of 5% solution must be added to get a mixture that is 8%?

Work each mixture problem. See Example 2. A certain metal is 20% tin. How many kilograms of this metal must be mixed with 80 kg of a metal that is 70% tin to get a metal that is 50% tin?

In a chemistry class, 12 L of a 12% alcohol solution must be mixed with a 20% solution to get a 14% solution. How many liters of the 20% solution are needed?

How many liters of a 10% alcohol solution must be mixed with 40 L of a 50% solution to get a 40% solution?

Minoxidil is a drug that has recently proven to be effective in treating male pattern baldness. Water must be added to 20 mL of a 4% minoxidil solution to dilute it to a 2% solution. How many milliliters of water should be used? (Hint: Water is 0% minoxidil.)

A pharmacist wishes to mix a solution that is 2% minoxidil. She has on hand 50 mL of a 1% solution, and she wishes to add some 4% solution to it to obtain the desired 2% solution. How much 4% solution should she add?

How many liters of a 60% acid solution must be mixed with a 75% acid solution to get 20 L of a 72% solution?

How many gallons of a 12% indicator solution must be mixed with a 20% indicator solution to get 10 gal of a 14% solution?

Work each investment problem using simple interest. See Example 3. Arlene Frank is saving money for her college education. She deposited some money in a savings account paying 5% and $1200 less than that amount in a second account paying 4%. The two accounts produced a total of $141 interest in 1 yr. How much did she invest at each rate?

Work each investment problem using simple interest. See Example 3. Margaret Fennell won a prize for her work. She invested part of the money in a certificate of deposit at 4% and $3000 more than that amount in a bond paying 6%. Her annual interest income was $780. How much did Margaret invest at each rate?

Work each investment problem using simple interest. See Example 3. An artist invests in a tax-free bond paying 6%, and $6000 more than three times as much in mutual funds paying 5%. Her total annual interest income from the investments is $825. How much does she invest at each rate?

Work each investment problem using simple interest. See Example 3. With income earned by selling the rights to his life story, an actor invests some of the money at 3% and $30,000 more than twice as much at 4%. The total annual interest earned from the investments is $5600. How much is invested at each rate?

Work each problem involving monetary values. See Example 4. A coin collector has $1.70 in dimes and nickels. She has two more dimes than nickels. How many nickels does she have?

Work each problem involving monetary values. See Example 4. A bank teller has $725 in $5 bills and $20 bills. The teller has five more twenties than fives. How many $5 bills does the teller have?

Work each problem involving monetary values. See Example 4. In May 2009, U.S. first-class mail rates increased to 44 cents for the first ounce, plus 17 cents for each additional ounce. If Sabrina spent $14.40 for a total of 45 stamps of these two denominations, how many stamps of each denomination did she buy? (Source: U.S. Postal Service.)

Work each problem involving monetary values. See Example 4. A movie theater has two ticket prices: $8 for adults and $5 for children. If the box office took in $4116 from the sale of 600 tickets, how many tickets of each kind were sold?

Work each problem involving monetary values. See Example 4. Harriet Amato operates a coffee shop. One of her customers wants to buy two kinds of beans: Arabian Mocha and Colombian Decaf. If she wants twice as much Mocha as Colombian Decaf, how much of each can she buy for a total of $87.50? (Prices are listed on the sign.)

Work each problem involving monetary values. See Example 4. Harriets Special Blend contains a combination of French Roast and Kona Deluxe beans. How many pounds of Kona Deluxe should she mix with 12 lb of French Roast to get a blend to be sold for $10 a pound?

Solve each problem involving distance, rate, and time. See Example 5. Which choice is the best estimate for the average rate of a bus trip of 405 mi that lasted 8.2 hr? A. 50 mph B. 30 mph C. 60 mph D. 40 mph

Solve each problem involving distance, rate, and time. See Example 5. Suppose that an automobile averages 45 mph and travels for 30 min. Is the distance traveled mi? If not, explain why not, and give the correct distance.

Solve each problem involving distance, rate, and time. See Example 5. A driver averaged 53 mph and took 10 hr to travel from Memphis to Chicago. What is the distance between Memphis and Chicago?

Solve each problem involving distance, rate, and time. See Example 5. A small plane traveled from Warsaw to Rome, averaging 164 mph. The trip took 2 hr. What is the distance from Warsaw to Rome?

Solve each problem involving distance, rate, and time. See Example 5. The winner of the 2008 Indianapolis 500 (mile) race was Scott Dixon, who drove his Dellara-Honda to victory at a rate of 143.567 mph. What was his time (to the nearest thousandth of an hour)? (Source: World Almanac and Book of Facts.)

Solve each problem involving distance, rate, and time. See Example 5. In 2008, Jimmie Johnson drove his Chevrolet to victory in the Brickyard 400 (mile) race at a rate of 115.117 mph. What was his time (to the nearest thousandth of an hour)? (Source: World Almanac and Book of Facts.)

In Exercises 3942, find the rate on the basis of the information provided. Use a calculator and round your answers to the nearest hundredth. All events were at the 2008 Olympics. (Source: World Almanac and Book of Facts.) 100-m hurdles, women Dawn Harper, USA 100 m 12.54 sec

In Exercises 3942, find the rate on the basis of the information provided. Use a calculator and round your answers to the nearest hundredth. All events were at the 2008 Olympics. (Source: World Almanac and Book of Facts.) 400-m hurdles, women Melanie Walker, Jamaica 400 m 52.64 sec

In Exercises 3942, find the rate on the basis of the information provided. Use a calculator and round your answers to the nearest hundredth. All events were at the 2008 Olympics. (Source: World Almanac and Book of Facts.) 400-m hurdles, men Angelo Taylor, USA 400 m 47.25 sec

In Exercises 3942, find the rate on the basis of the information provided. Use a calculator and round your answers to the nearest hundredth. All events were at the 2008 Olympics. (Source: World Almanac and Book of Facts.) 400-m run, men LaShawn Merritt, USA 400 m 43.75 sec

Solve each motion problem. See Examples 6 and 7. Atlanta and Cincinnati are 440 mi apart. John leaves Cincinnati, driving toward Atlanta at an average rate of 60 mph. Pat leaves Atlanta at the same time, driving toward Cincinnati in her antique auto, averaging 28 mph. How long will it take them to meet?

Solve each motion problem. See Examples 6 and 7. St. Louis and Portland are 2060 mi apart. A small plane leaves Portland, traveling toward St. Louis at an average rate of 90 mph. Another plane leaves St. Louis at the same time, traveling toward Portland and averaging 116 mph. How long will it take them to meet?

Solve each motion problem. See Examples 6 and 7. A train leaves Kansas City, Kansas, and travels north at 85 km per hr. Another train leaves at the same time and travels south at 95 km per hour. How long will it take before they are 315 km apart?

Solve each motion problem. See Examples 6 and 7. Two steamers leave a port on a river at the same time, traveling in opposite directions. Each is traveling at 22 mph. How long will it take for them to be 110 mi apart?

Solve each motion problem. See Examples 6 and 7. From a point on a straight road, Marco and Celeste ride bicycles in the same direction. Marco rides at 10 mph and Celeste rides at 12 mph. In how many hours will they be 15 mi apart?

Solve each motion problem. See Examples 6 and 7. At a given hour, two steamboats leave a city in the same direction on a straight canal. One travels at 18 mph and the other travels at 24 mph. In how many hours will the boats be 9 mi apart?

Solve each motion problem. See Examples 6 and 7. Two planes leave an airport at the same time, one flying east, the other flying west. The eastbound plane travels 150 mph slower. They are 2250 mi apart after 3 hr. Find the rate of each plane.

Solve each motion problem. See Examples 6 and 7. Two trains leave a city at the same time. One travels north, and the other travels south 20 mph faster. In 2 hr, the trains are 280 mi apart. Find their rates.

Solve each motion problem. See Examples 6 and 7. Two cars start from towns 400 mi apart and travel toward each other. They meet after 4 hr. Find the rate of each car if one travels 20 mph faster than the other.

Solve each motion problem. See Examples 6 and 7. Two cars leave towns 230 km apart at the same time, traveling directly toward one another. One car travels 15 km per hr slower than the other. They pass one another 2 hr later. What are their rates?

Solve each problem. Kevin is three times as old as Bob. Three years ago the sum of their ages was 22 yr. How old is each now? (Hint: Write an expression first for the age of each now and then for the age of each three years ago.)

Solve each problem. A store has 39 qt of milk, some in pint cartons and some in quart cartons. There are six times as many quart cartons as pint cartons. How many quart cartons are there? (Hint: 1 qt 2 pt)

Solve each problem. A table is three times as long as it is wide. If it were 3 ft shorter and 3 ft wider, it would be square (with all sides equal). How long and how wide is the table?

Solve each problem. Elena works for $6 an hour. A total of 25% of her salary is deducted for taxes and insurance. How many hours must she work to take home $450?

Solve each problem. Paula received a paycheck for $585 for her weekly wages less 10% deductions. How much was she paid before the deductions were made?

Solve each problem. At the end of a day, the owner of a gift shop had $2394 in the cash register. This amount included sales tax of 5% on all sales. Find the amount of the sales.

Decide whether each statement is true or false. See Section 1.4. 6 7 6

Decide whether each statement is true or false. See Section 1.4. 10 10

Decide whether each statement is true or false. See Section 1.4. -4 -3

Decide whether each statement is true or false. See Section 1.4. -11 7 -9

Decide whether each statement is true or false. See Section 1.4. 0 7 - 1 2

Graph the numbers on a number line. -3, - See Section 1.4.