Back to Intermediate Algebra 2e

2.2 Use a Problem Solving Strategy

Turning word problems into equations with a step-by-step method, applied to number puzzles, percent change, and simple interest.

Intermediate Algebra 2e, 2.2 Use a Problem Solving Strategy

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78 exercises

2.2 Exercise 1

Before you get started, take this readiness quiz.

Translate “six less than twice x” into an algebraic expression.
If you missed this problem, review the reference.

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2.2 Exercise 2

Convert 4.5% to a decimal.
If you missed this problem, review the reference.

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2.2 Exercise 3

Convert 0.6 to a percent.
If you missed this problem, review the reference.

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2.2 Exercise 5

Guillermo bought textbooks and notebooks at the bookstore. The number of textbooks was three more than twice the number of notebooks. He bought seven textbooks. How many notebooks did he buy?

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2.2 Exercise 6

Gerry worked Sudoku puzzles and crossword puzzles this week. The number of Sudoku puzzles he completed is eight more than twice the number of crossword puzzles. He completed 22 Sudoku puzzles. How many crossword puzzles did he do?

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2.2 Exercise 8

The sum of four times a number and two is fourteen. Find the number.

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2.2 Exercise 9

The sum of three times a number and seven is twenty-five. Find the number.

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2.2 Exercise 11

The sum of two numbers is negative twenty-three. One number is seven less than the other. Find the numbers.

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2.2 Exercise 12

The sum of two numbers is negative eighteen. One number is forty more than the other. Find the numbers.

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2.2 Exercise 14

Find three consecutive integers whose sum is −96.−96 .

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2.2 Exercise 15

Find three consecutive integers whose sum is −36.−36 .

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2.2 Exercise 16

Find three consecutive even integers whose sum is 120120.

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2.2 Exercise 17

Find three consecutive even integers whose sum is 102.

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2.2 Exercise 18

Find three consecutive even integers whose sum is −24.−24 .

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2.2 Exercise 19

A married couple together earns $110,000 a year. The wife earns $16,000 less than twice what her husband earns. What does the husband earn?

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2.2 Exercise 20

According to the National Automobile Dealers Association, the average cost of a car in 2014 was $28,400. This was $1,600 less than six times the cost in 1975. What was the average cost of a car in 1975?

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2.2 Exercise 21

US Census data shows that the median price of new home in the U.S. in November 2014 was $280,900. This was $10,700 more than 14 times the price in November 1964. What was the median price of a new home in November 1964?

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2.2 Exercise 23

Translate and solve: ⓐ What number is 45% of 80? ⓑ 7.5% of what amount is $1.95? ⓒ 110 is what percent of 88?

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2.2 Exercise 24

Translate and solve: ⓐ What number is 55% of 60? ⓑ 8.5% of what amount is $3.06? ⓒ 126 is what percent of 72?

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2.2 Exercise 26

One serving of wheat square cereal has 7 grams of fiber, which is 28% of the recommended daily amount. What is the total recommended daily amount of fiber?

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2.2 Exercise 27

One serving of rice cereal has 190 mg of sodium, which is 8% of the recommended daily amount. What is the total recommended daily amount of sodium?

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2.2 Exercise 29

Mitzi received some gourmet brownies as a gift. The wrapper said each brownie was 480 calories, and had 240 calories of fat. What percent of the total calories in each brownie comes from fat? Round the answer to the nearest whole percent.

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2.2 Exercise 30

The mix Ricardo plans to use to make brownies says that each brownie will be 190 calories, and 76 calories are from fat. What percent of the total calories are from fat? Round the answer to the nearest whole percent.

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2.2 Exercise 32

Find the percent change. (Round to the nearest tenth of a percent.) In 2011, the IRS increased the deductible mileage cost to 55.5 cents from 51 cents.

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2.2 Exercise 33

Find the percent change. (Round to the nearest tenth of a percent.) In 1995, the standard bus fare in Chicago was $1.50. In 2008, the standard bus fare was 2.25.

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2.2 Exercise 35

Find ⓐ the amount of mark-up and ⓑ the list price: Jim’s music store bought a guitar at original cost $1,200. Jim marked the price up 50%.

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2.2 Exercise 36

Find ⓐ the amount of mark-up and ⓑ the list price: The Auto Resale Store bought Pablo’s Toyota for $8,500. They marked the price up 35%.

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2.2 Exercise 37

Areli invested a principal of $950 in her bank account that earned simple interest at an interest rate of 3%. How much interest did she earn in five years?

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2.2 Exercise 38

Nathaly deposited $12,500 in her bank account where it will earn 4% simple interest. How much interest will Nathaly earn in five years?

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2.2 Exercise 39

Susana invested a principal of $36,000 in her bank account that earned simple interest at an interest rate of 6.5%.6.5 \% . How much interest did she earn in three years?

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2.2 Exercise 40

Hang borrowed $7,500 from her parents to pay her tuition. In five years, she paid them $1,500 interest in addition to the $7,500 she borrowed. What was the rate of simple interest?

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2.2 Exercise 41

Jim lent his sister $5,000 to help her buy a house. In three years, she paid him the $5,000, plus $900 interest. What was the rate of simple interest?

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2.2 Exercise 42

Loren lent his brother $3,000 to help him buy a car. In four years, his brother paid him back the $3,000 plus $660 in interest. What was the rate of simple interest?

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2.2 Exercise 43

Sean’s new car loan statement said he would pay $4,866.25 in interest from a simple interest rate of 8.5% over five years. How much did he borrow to buy his new car?

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2.2 Exercise 44

Eduardo noticed that his new car loan papers stated that with a 7.5% simple interest rate, he would pay $6,596.25 in interest over five years. How much did he borrow to pay for his car?

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2.2 Exercise 45

In five years, Gloria’s bank account earned $2,400 interest at 5% simple interest. How much had she deposited in the account?

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2.2 Exercise 46

Use a Problem Solving Strategy for Word Problems

List five positive thoughts you can say to yourself that will help you approach word problems with a positive attitude. You may want to copy them on a sheet of paper and put it in the front of your notebook, where you can read them often.

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2.2 Exercise 48

Solve using the problem solving strategy for word problems. Remember to write a complete sentence to answer each question.

There are 16 girls in a school club. The number of girls is four more than twice the number of boys. Find the number of boys.

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2.2 Exercise 50

Solve using the problem solving strategy for word problems. Remember to write a complete sentence to answer each question.

Huong is organizing paperback and hardback books for her club’s used book sale. The number of paperbacks is 12 less than three times the number of hardbacks. Huong had 162 paperbacks. How many hardback books were there?

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2.2 Exercise 52

Solve each number word problem.

The difference of a number and 12 is three. Find the number.

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2.2 Exercise 54

Solve each number word problem.

The sum of three times a number and eight is 23. Find the number.

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2.2 Exercise 56

Solve each number word problem.

The difference of twice a number and seven is 17. Find the number.

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2.2 Exercise 58

Solve each number word problem.

Three times the sum of a number and nine is 12. Find the number.

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2.2 Exercise 60

Solve each number word problem.

One number is six more than the other. Their sum is 42. Find the numbers.

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2.2 Exercise 62

Solve each number word problem.

The sum of two numbers is 20. One number is four less than the other. Find the numbers.

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2.2 Exercise 64

Solve each number word problem.

One number is 14 less than another. If their sum is increased by seven, the result is 85. Find the numbers.

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2.2 Exercise 66

Solve each number word problem.

The sum of two numbers is 14. One number is two less than three times the other. Find the numbers.

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2.2 Exercise 68

Solve each number word problem.

The sum of two consecutive integers is 77. Find the integers.

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2.2 Exercise 70

Solve each number word problem.

The sum of three consecutive integers is 78. Find the integers.

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2.2 Exercise 72

Solve each number word problem.

Find three consecutive integers whose sum is −36.−36 .

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2.2 Exercise 74

Solve each number word problem.

Find three consecutive even integers whose sum is 258.

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2.2 Exercise 76

Solve each number word problem.

Find three consecutive odd integers whose sum is −213.−213 .

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2.2 Exercise 78

Solve each number word problem.

Philip pays $1,620 in rent every month. This amount is $120 more than twice what his brother Paul pays for rent. How much does Paul pay for rent?

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2.2 Exercise 80

Solve each number word problem.

Laurie has $46,000 invested in stocks and bonds. The amount invested in stocks is $8,000 less than three times the amount invested in bonds. How much does Laurie have invested in bonds?

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2.2 Exercise 82

Translate and solve.

ⓐ What number is 45% of 120? ⓑ 81 is 75% of what number? ⓐ What percent of 260 is 78?

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2.2 Exercise 84

Translate and solve.

ⓐ 250% of 65 is what number? ⓑ 8.2% of what amount is $2.87? ⓐ 30 is what percent of 20?

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2.2 Exercise 86

Solve.

Geneva treated her parents to dinner at their favorite restaurant. The bill was $74.25. Geneva wants to leave 16% of the total bill as a tip. How much should the tip be?

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2.2 Exercise 88

Solve.

One serving of oatmeal has 8 grams of fiber, which is 33% of the recommended daily amount. What is the total recommended daily amount of fiber?

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2.2 Exercise 90

Solve.

A bacon cheeseburger at a popular fast food restaurant contains 2070 milligrams (mg) of sodium, which is 86% of the recommended daily amount. What is the total recommended daily amount of sodium?

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2.2 Exercise 92

Solve.

The nutrition fact sheet at a fast food restaurant says the fish sandwich has 380 calories, and 171 calories are from fat. What percent of the total calories is from fat?

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2.2 Exercise 94

Solve.

Emma gets paid $3,000 per month. She pays $750 a month for rent. What percent of her monthly pay goes to rent?

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2.2 Exercise 96

Solve.

Tamanika received a raise in her hourly pay, from $15.50 to $17.36. Find the percent change.

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2.2 Exercise 98

Solve.

Annual student fees at the University of California rose from about $4,000 in 2000 to about $12,000 in 2010. Find the percent change.

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2.2 Exercise 100

Solve.

A grocery store reduced the price of a loaf of bread from $2.80 to $2.73. Find the percent change.

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2.2 Exercise 102

Solve.

Hernando’s salary was $49,500 last year. This year his salary was cut to $44,055. Find the percent change.

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2.2 Exercise 104

Find ⓐ the amount of discount and ⓑ the sale price.

Janelle bought a beach chair on sale at 60% off. The original price was $44.95.

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2.2 Exercise 106

Find ⓐ the amount of discount and ⓑ the discount rate (Round to the nearest tenth of a percent if needed.)

Larry and Donna bought a sofa at the sale price of $1,344. The original price of the sofa was $1,920.

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2.2 Exercise 108

Find ⓐ the amount of the mark-up and ⓑ the list price.

Daria bought a bracelet at original cost $16 to sell in her handicraft store. She marked the price up 45%. What was the list price of the bracelet?

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2.2 Exercise 110

Find ⓐ the amount of the mark-up and ⓑ the list price.

Tom paid $0.60 a pound for tomatoes to sell at his produce store. He added a 33% mark-up. What price did he charge his customers for the tomatoes?

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2.2 Exercise 112

Solve.

Casey deposited $1,450 in a bank account that earned simple interest at an interest rate of 4%. How much interest was earned in two years?

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2.2 Exercise 114

Solve.

Robin deposited $31,000 in a bank account that earned simple interest at an interest rate of 5.2%. How much interest was earned in three years?

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2.2 Exercise 116

Solve.

Hilaria borrowed $8,000 from her grandfather to pay for college. Five years later, she paid him back the $8,000, plus $1,200 interest. What was the rate of simple interest?

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2.2 Exercise 118

Solve.

Lebron lent his daughter $20,000 to help her buy a condominium. When she sold the condominium four years later, she paid him the $20,000, plus $3,000 interest. What was the rate of simple interest?

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2.2 Exercise 120

Solve.

In 10 years, a bank account that paid 5.25% simple interest earned $18,375 interest. What was the principal of the account?

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2.2 Exercise 122

Solve.

Joshua’s computer loan statement said he would pay $1,244.34 in simple interest for a three-year loan at 12.4%. How much did Joshua borrow to buy the computer?

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2.2 Exercise 124

Tipping At the campus coffee cart, a medium coffee costs $1.65. MaryAnne brings $2.00 with her when she buys a cup of coffee and leaves the change as a tip. What percent tip does she leave?

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2.2 Exercise 126

What has been your past experience solving word problems? Where do you see yourself moving forward?

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2.2 Exercise 128

After returning from vacation, Alex said he should have packed 50% fewer shorts and 200% more shirts. Explain what Alex meant.

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Adapted from Intermediate Algebra 2e © 2020 Rice University. Licensed under CC BY 4.0. Source: Intermediate Algebra 2e. Imported at revision 77a933c.