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214

7

9(2 )b b

b = 1.8 or 1 4/549

y = 8

Solve.

1. 2.

3.

ANSWER

ANSWERANSWER

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Write the formula

for work problems.

7

4 3 4

x x

b = 1.8 or 1 4/549

y = 8

Solve.

1. 2.

3.

ANSWER

ANSWERANSWER

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42510011 0010 1010 1101 0001 0100 1011

Work ProblemsObjective: To solve Work Problems

(work rate x time = work done)

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Work Problems• To do work problems

you must remember three things.

•1. When working together, one person does part of the job (a fractional amount).

•2. The sum of the parts equals a whole job.

•3. To solve the equation, you must get common denominators.

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One More Thing…• Write your final answer in

sentence form and check your solution for reasonableness and accuracy.

• Yes, word problems are difficult, but they are not impossible… with the right organization and persistence.

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Work ProblemsSean can conquer a video game alone in 6 hours. If he works/plays for 2 hours, what part of the job is done?

EX. 1

Part completed

Time working alone

2

6

hours

hours

1

3 of the job is

completed

If more than one person is working

together to complete a task,

then the part that each person does,

will add up to equal the job.

If more than one person is working

together to complete a task,

then the part that each person does,

will add up to equal the job.

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An equation that models this is as follows:-2 people working together:

1

AloneTime

TogetherTime

AloneTime

TogetherTime

-3 people working together:

1

AloneTime

TogetherTime

AloneTime

TogetherTime

AloneTime

TogetherTime

Formula 1

Formula 2

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4

x

If Jeremy can beat Halo alone in 6 hours and Jeff can beat Halo alone in 4 hours, how long will it take if they both worked (play) together? (NOTE: The answer of 5 hours is not correct; the answer MUST BE less than 4 hours!)

EX. 2

Jeremy working + Jeff working = 1 Halo conquered Use

Formula

1 6

x1

Work Problems

1 2 1 2 1 2

LCD=12

2x

3x

12

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2x + 3x = 12

5x = 12

22

52.4

x

hours

12 22

5 5x

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6

x 1

If one hose can fill a pool in 12 hours, another hose can fill the pool in 8 hours, and a different hose can fill the pool in 6 hours, how long will it take if all three hoses are working together to fill the pool?

EX. 3

hose A + hose B + hose C = 1 pool filled Use

Formula

212

x

24 24 24 24

LCD=24

2x

3x

24

8

x

Work Problems

4x

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2x + 3x + 4x = 24

9x = 24

22

32.7

x

hours

24 62

9 9x

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