2. Work Problems
 Problems involving work done at a steady pace, such as
mowing a lawn, can be solved using this formula:
 In the formula, the work rate is the part of a job that is
completed in a given amount of time.
 Example: if you take 2 hours to mow a lawn, then your
work rate is ½ job per hour.

3. Example 1
Find the time it takes to complete a job
GROCERY STORE
You and a co-worker share responsibilities at a grocery
store. You take 40 minutes to place sales tags under
each item that is on sale, and your co-worker takes 60
minutes to complete the same job. How long will it take
the two of you to place all of the sales tags if you work
together?

4. Example 1
Find the time it takes to complete a job
SOLUTION
STEP 1 Find the work rates for you and your coworker. Because you can do the entire job in
1
40 minutes, your work rate is
job per
40
1
minute. Your co-worker’s work rate is
job
60
per minute.
STEP 2 Find the part of the job done by each person.
Let t be the time (in minutes) you take to
complete the job together.

5. Example 1
Find the time it takes to complete a job
Your work done:
1
t
•t =
40
40
Co-worker’s work done:
1
t
•t =
60
60
STEP 3 Write an equation for the total work done. Then
solve the equation. The parts of the job found
in Step 2 must add up to 1 whole job.
t
t
+
=1
40 60
3t + 2t = 120
t = 24
Write equation.
Multiply each side by LCD, 120.
Solve for t.

6. Example 1
Find the time it takes to complete a job
ANSWER
Together, you and your co-worker can place the sales
tags in 24 minutes.

7. Example 2
Multiple Choice Practice
Together, you and your cousin can paint a room in 8
hours. Your cousin takes twice as long to paint the room
by himself as you take to paint the room alone. How long
would your cousin take to paint the room by himself?
10 hours
12 hours
18 hours
24 hours

8. Example 2
Multiple Choice Practice
SOLUTION
STEP 1 Find the work rates for you and your cousin.
Let t be the number of hours you take to paint
the room alone. Your work rate is 1 job per
t
hour. Because your cousin takes twice as long,
or 2t hours, to paint the room, his work rate is
1 job per hour.
2t
STEP 2 Find the work done by each person. You and
your cousin both work for 8 hours.

9. Example 2
Multiple Choice Practice
1
8
Your work done: • 8 =
t
t
1
8
4
•8=
Cousin’s work done:
=
2t
2t
t
STEP 3 Write an equation for the total work done. Then
solve the equation. Because the parts of the
job completed by you and your cousin make up
1 whole job, set the sum of these expressions
equal to 1.
8
4
+ =1
t
t
Write equation.

10. Example 2
Multiple Choice Practice
12
=1
t
Add.
12 = t
Multiply both sides by t.
STEP 4 Find the time it takes your cousin to complete
the job by himself.
Because you take 12 hours to paint the room
by yourself, your cousin will take twice as
long, or 24 hours, to paint the room alone.
ANSWER
The correct answer is D.