Solving Word

Problems: The

Value of Money and Percents

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Example

A business executive rented a car. The Supreme Car

Rental Agency charged $39 per day and $0.28 per mile.

The executive rented the car for two days and the total rental cost was computed to be $176. How many miles did the executive drive the rented car?

1. Understand the problem.

Let m = the number of miles driven

2. Write an equation. per day cost + mileage cost = total cost

39(2) + 0.28m

= 176

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Example (cont)

3. Solve and state the answer.

39(2) +

0.28m

= 176

78 + 0.28m = 176

0.28m = 98 m = 350

The executive drove 350 miles.

4. Check.

39(2) + 0.28(350) = 176

78 + 98 = 176

176 = 176

Copyright © 2013, 2010, 2006, 2003 Pearson Education, Inc.

Example

A sofa was marked down with the following sign: “The price of this sofa has been reduced by 23%. You can save $138 if you buy now.” What was the original price of the sofa?

1. Understand the problem.

Let s = the original price of the sofa.

Let 0.23s = the amount of the price reduction, which is $138

2. Write an equation and solve.

0.23s = 138 s = 600

The original price of the sofa was $600.

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Example

Kylie received a pay raise this year. The raise was 3% of last year’s salary. This year she will receive $35,535.

What was her salary last year before the raise?

1. Understand the problem.

Let x = Kylie’s salary last year

0.03 = the amount of the raise

2. Write an equation and solve. last year’s salary + the amount of raise = new salary x +

0.03x

= 35,535

1.03x = 35,535 x = 34,500

The check is left to you.

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Solving Simple Interest Problems

Simple interest = principal ∙ rate ∙ time

I=P∙R∙T

The interest rate is assumed to be per year unless otherwise stated. The time T must be in years.

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Example

Find the interest on a loan of $2500 that is