Page 100 - Basic College Mathematics with Early Integers

S E C T ION 1. 8 I AN INTRODUCTION TO PROBLEM SOLVING 77

4. INTERPRET. Check your work. The answer is reasonable since 206 R 12 is
close to our estimate of 200. State your conclusion: 206 cases will be filled, with
12 cans left over.There will be enough cases to fill an order for 200 cases.

Work Practice 2

Example 3 Calculating Budget Costs PRACTICE 3
The director of a learning lab at a local community college is working on next The director of the learning lab
year’s budget. Thirty-three new DVD players are needed at a cost of $187 each. also needs to include in the
What is the total cost of these DVD players? budget a line for 425 blank CDs
at a cost of $4 each.What is this
Solution:
total cost for the blank CDs?
1. UNDERSTAND. Read and reread the problem, and then draw a diagram.

33 DVD Players

…
$ 187 $ 187 $ 187

From the phrase “total cost,” we might decide to solve this problem by adding.
This would work, but repeated addition, or multiplication, would save time.
2. TRANSLATE.
number of cost of a
In words: Total cost is times
DVD players DVD player

T T T T T
Translate: Total cost = 33 * $187
3. SOLVE: Once again, let’s estimate a reasonable solution.
187 rounds to 200
* 33 rounds to * 30
561 6000 estimate
5610
6171 exact

4. INTERPRET. Check your work. State your conclusion: The total cost of the
DVD players is $6171.

Work Practice 3
PRACTICE 4
In 2008, the average salary for a
Example 4 Calculating a Public School Teacher’s Salary public school teacher in Alaska
was $56,758. For the same year,
In 2008, the average salary of a public school teacher in California was $64,424. the average salary for a public
For the same year, the average salary for a public school teacher in Iowa was school teacher in Hawaii was
$17,760 less than this. What was the average public school teacher’s salary in $3358 less than this.What was
Iowa? (Source: National Education Association)
the average public school
Solution: teacher’s salary in Hawaii?
(Source: National Education
1. UNDERSTAND. Read and reread the problem. Notice that we are told that Association)
the Iowa salary is $17,760 less than the California salary.The phrase “less than”
indicates subtraction. Answers
Continued on next page 3. $1700 4. $53,400