Basic Mathematics for College Students

1. a. b. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
   7
   12

3

5

3

20

23

24



45

8



3

2

9

35

9

10

2

3



6

11

7

9

1

2

ANSWERS TO SELF CHECKS

3.4 Adding and Subtracting Fractions 251

SolveWe must find the sum of three fractions with different denominators. To
find the LCD, we prime factor the denominators and use each prime factor the
greatestnumber of times it appears in any one factorization:

~

~

The LCD for and is 60.

This fraction is in simplest form.

StateThe fraction of the student body that watches 0 to 2 hours of TV daily is

CheckWe can check by estimation. The result, is approximately which
simplifies to The red, yellow, and blue shaded areas appear to shade
about of the pie chart. The result seems reasonable.^56

5

6.

50

60 ,

53

60 ,

53

60.



53

60

Add the numerators and write the sum

over the common denominator 60.



10  15  28

60

Multiply the numerators. Multiply the

 (^) denominators. The denominators are now the same.

10

60



15

60



28

60

Build each fraction so that its

denominator is 60.

1

6



1

4



7

15



1

6



10

10



1

4



15

15



7

15



4

4

7

15

1

4

,

1

6

,

2 appears twice in the factorization of 4.

3 appears once in the factorization

of 6 and 15.

5 appears once in the factorization of 15.

¶LCD 2  2  3  5  60

6  2  3

4  2  2

15  3  5

“Putting together a budget is crucial if you don’t want to spend your way into

serious problems. You’re also developing a habit that can serve you well throughout

your life.”

Liz Pulliam Weston, MSN Money

The circle graph below shows a suggested budget for new college graduates as

recommended by Springboard, a nonprofit consumer credit counseling service.

What fraction of net take-home pay should be spent on housing?

Housing:?

Personal:– 201 –

Savings:––^1 Medical:–– 252

20

Clothing:–– 251

Debt:–– 101

Food:––^1

10

Transportation:–– 203

Utilities:––^2

25

THINK IT THROUGH Budgets

1

1

0

15

 28

53